Allpar Forums banner

Forum Discussions about this Product

1 - 4 of 4 Posts
    1. · Premium Member
      3,295 Posts
      The 1970-1974 Dodge Challenger

      by Kelly Doke and the Allpar staff

      See Challenger T/A and Challenger R/T

      1964 was a important time in the Challenger's history, though the car had not yet been created. John Z. Delorean converted the Tempest into the GTO, a car that had young buyers flocking to Pontiac to get their own high-octane-burning cheap thrills. Then, in April, rivals from Dearborn unveiled the Mustang at the World's Fair, grabbing attention and sales despite Plymouth quietly beating them to the punch, weeks earlier, with the Barracuda.

      In terms of power, Dodge was no slouch that year. Tom Hoover's brainchild, the 426 Hemi, loosely based on the 426 Max Wedge, dominated Daytona and much of the NASCAR season. To Lynn Townsend's chagrin (or perhaps to his credit), a few 330s with Hemi power were clandestinely let loose on Woodward.

      It didn't take a marketing analyst to figure out that the children of the baby boomers were becoming financially aware, and the proliferation of Mustangs and GTOs on the streets were proof of that. Chrysler had to make a move, and make one fast. Thus, in 1968, Plymouth launched the popular Road Runner, which took off like wildfire. Still, some believe they needed a small, lithe, agile compact, much like the "Panther" project GM was cooking up. While the Valiant and Dart had athletic aspirations, they were no match for the Camaro and Firebird.

      A sporty car based on the Dart and Valiant (as the Barracuda had been, and the Duster would be) could be perfect. Burton Bouwkamp, product planner, wrote that, in 1967, 1.5 million specialty compacts were predicted for 1970; and Chrysler predicted market penetration of 15%, for 225,000 cars per year. They could, based on those projections, easily make 200,000 Challengers and Barracudas, perfect for plant scheduling.

      Clay models for the new "pony car" started taking shape, literally, in 1967. Late 1968, Bill Brownlie and Carl Cameron's mockups looked almost production ready. Roger Struck (Dart/Challenger Product Planner in 1967) wrote,

      I was in the styling studio one day when Elwood Engle (VP of design) was reviewing the exterior design of the "'E' Body" Challenger clay model. Elwood suggested to Bill Brownlie (Dodge design chief) that the main character line along the side of the model (I think we called it the "B" line) was a little low and to bring it up so it didn't have a dragging appearance.
      In 1968, another event altered the course of the Challenger's evolution. Over at General Motors, Semon "Bunkie" Knudsen had, years earlier, imposed a moratorium on engines larger than 400 cubic inches in the mid-sized (A-Body) model range, along with a ban in official factory participation in motorsports. That year, Pandora's Box was opened with the end of that moratorium, and a 455 cubic inch V8 appeared on the option list for the Cutlass 442. Others followed: Camaros with 427s, Mustangs with 428s.

      This was a new problem for Chrysler. The new pony car was only intended to have the 383 as the largest engine (the most the Barracuda could handle), but still remain based on the A-body, as the Barracuda was (the Barracuda itself could only barely handle the 383, and most reviewers preferred the lighter 340). 716 pounds of Detroit pig iron up front in the form of the Hemi wouldn't translate well for a platform based on agility. Chrysler had seen its share of headaches in the Hurst Hemi Darts and Barracudas, and even in the 440 Darts and Valiants. A big motor in a small car, on the manufacturing scale that Chrysler needed, wasn't feasible. Again, to quote Burton Bouwkamp:

      The original form was the Barracuda derived from an A Body. We had
      experience with that approach and knew that we could not get a competitive
      sporty proportion and B engine options with an A Body plarform. The B engine option forced a wider car. Also we had to add width
      for provision for bigger wheels/tires. The additional width helped
      appearance but of course it added weight and cost.
      The new car would have to use the B-body cowl (radiator core support to firewall), and most of the underpinnings of the larger cars.
      The E-body tag reflected current Chrysler Corp. body styles: the compacts were As, mid-size to large were B, and C and D were reserved for oversized Chrysler models. [Challenger creation stories]

      In terms of safety, Challenger and Barracuda alone got a new energy-absorbing steering column, added roof rollover protection, crash-resistant inner door beams, and safer latch strikers and door handles.

      The 1970 Dodge Challenger arrives

      Friday, August 1, 1969 saw a fervor of excitement at Line One and Line Two at Dodge Main in Hamtramck. While numerous plants around the country were producing new 1970 Plymouths, Dodges, Chryslers, and Imperials, Dodge Main was, for the moment, the only one constructing the all-new Challenger and its platform sibling, the Barracuda. (Van Nuys Plant in Los Angeles would begin weeks later.)

      The new Dodge pony car rode on a 111-inch wheelbase, while the high-strung 'Cuda had a shorter 108 inches, spindle to axle. The cars shared some parts, glass, underpinnings, and interior trim pieces, but were still unique to each other. The Challenger had enough options, trim packages, and colors (18, including the Hi-Impact colors that added $14.70 to the bottom line) for the most discerning consumer. With styling echoing the contemporary Chevrolet Camaro, and with the Mercury Cougar and Pontiac Firebird market segment in its crosshairs, this car was envisioned for "The Peformance Guy Who Is Married With Two Kids."

      At Dodge Main, the Challengers were built on two dedicated lines, the R/T models, and convertibles would be built on line 1, along with any big block specialty cars. Line Two would see any Challenger (non-R/T, 383 engine and smaller) that didn't have a big motor or no top built alongside six cylinder Darts, 318 Chargers, and Coronet sedans. A quick check of a fender tag will annotate that by a "LN1 or LN2" on the fender tag.

      On the outside, the Challenger featured new, flush pull-up door handles, a new interior door lock recessed in the armrest, and high-back bucket seats with built in head restraints, or bench seats with folding center armrests in the Hardtop. Paint schemes included the colors Plum Crazy, HEMI Orange, and accented "bumblebee stripes." Door glass had no vents and was curved. Roger Struck wrote:

      Colin Neale (chief of interior design) loved the sculptured look of the plastic molded door trim panels. He said he would "soften" the hard touch of the molded panel with a textured surface. Well, it was still hard---texture or no ... it had a cost advantage as well as the 3-D freedom of a molded part, but it was unfriendly to the touch and had no sound dampening quality and, therefore exaggerated any rattles in the door.
      Burton Bouwkamp added, "The polypropylene material was unstable and every door panel was a little different dimensionally which made a problem for Car Assembly. The material was flexible so the assembler could force it to fit."

      Optional on Special Edition was an overhead console with low-fuel, door-ajar, and seat-belt lights. Seats could be manually tilted and moved fore and aft, or up and down; they were counterbalanced with springs to make movement easier. A stereo tape player, cruise control, rear defogger, power windows, headlight delay, and other luxury items were optional. Safety precautions included a collapsible steering column, two-piece door impact beam, and a box-section roll bar.

      A Slap-Stik Shift Gate was sold with the console-mounted TorqueFlite; 60-series tires were on 15 inch wheels, fairly aggressive for the time, as long as you got an engine beyond the non-Magnum 383 (such as the 340 or 383 Magnum); the 225, 318, and 383 non-Magnum engines came with 14 inch wheels. Tires (fiberglass belted) ranged from E78 to F60 (Hemi only). Wheels were 5.5 inches wide, except for the 340 and Hemi, whose wheels were 7 inches wide.

      The Challenger R/T started with a 383 cubic inch V8, with a 9.5:1 compression ratio and 335 gross hp at 5,200 rpm; torque was 425 lb-ft at 3,400 rpm. The premium-fuel-only powerplant had a single four-barrel Holley carb, hydraulic lifters, overhead rocker arms, and dual, reverse-flow mufflers.

      The standard transmission was a three-speed floor shift with a 2.55:1 first, 1.49:1 second, and 1:1 third; cam timing was 268° intake duration, 284° exhaust duration. Heavy duty drum brakes were standard, along with a rallye instrument cluster (including tachometer, trip odometer, variable speed wipers, 150 mph speedometer, and oil pressure gauge); a bumblebee stripe or longitudinal tape stripe were optional, at no extra cost. Vinyl bucket seats with head restraints and a 3-spoke "simulated walnut" steering wheel helped complete the package (Rick Ehrenberg of Mopar Action noted that these tend to wear out relatively quickly).

      Safety features included dual channel brakes, padded instrument panel, day/night rearview mirror (standard on R/T), seat belts in all positions, and an energy absorbing steering column.

      According to a contemporary brochure, legendary record-setting drag racer Don Garlits said:

      They watched the whole pony car thing develop, then built their own super-tough version... the Challenger R/T. Compact like a Dart. Wide like a Charger. Just the right size for anyone who likes his own personalized backyard bomb. Dodge should sell a million of 'em. Challenger and especially Challenger R/T are young people's cars with young persons' price tags."
      Los Angeles-built cars only had one line at the plant in Van Nuys, so a big block R/T could be built in sequence after a Dart Sedan. No Hemi or Six Pack cars came from the Los Angeles plant, due to the extra chassis work necessary for those cars.

      A special Hemi Challenger Convertible, the first off the line, was converted into the Dodge Yellowjacket, making the car show circuit for the 1969 season. Painted a honey-gold color, it showcased styling elements for future offerings.

      The grille of the car was a harbinger for the '71 model year cars, with a distant rear panel treatment of the '72-'74 cars, and a targa type roof, with fully-faired headrests that stylistically flowed into the rear decklid, much like the Jaguar E-type of the fifties and the Thunderbird roadsters of the early sixties. At the New York and Los Angeles Shows, a beautiful woman was displayed with the car, wearing as little as possible in that era, and served as a living canvas. Passerby could draw on her with markers to their heart's content. The car was largely overlooked. It would reappear the next year as the Dodge Diamante, and thanks to a scratch recieved somewhere between shows, it was now a pearl white.

      The second incarnation of the car would have taillights that would be directly duplicated on the '72-'74 cars, and an aerodynamic rubber-coated nose, much like the Elastomeric bumpered cars of the era, along with pop-up headlights. Steven Juliano owns the Diamante now, and it has been restored to its 1970 show season status.

      When the Challenger hit showroom floors in the fall, Chrysler expected to send 200,000 units to new homes, so all aspects of the market had been covered, with the low end Deputy Coupe, the bread-and-butter Highline coupes, sizzling hot convertibles, the agile T/A, the posh Special Editions, and the pulse-quickening R/Ts, with two 440s, a stout 383, and the coveted 426 Hemi. These cars were the first in the industry to utilize injection-molded plastic interior panels, and T/As were also the first in the industry to utilize different sized tires on the front and rear axles.

      1970 Dodge Challenger models

      For 1970, there were numerous Dodge Challenger models, from the low-end (late-introduction) Deputy to the limited-edition top-end T/A, with the luxury SE and hot R/T in between. The company was planning on 200,000 sales, and the wide range of models reflected that.


      The model year had started out with the Challenger Highline, JH23, and unlike the Deputy, it was available in almost every trim and luxury option. The base engine was the humble slant six, but the "starter" V8 was the 340, producing a rated 275 hp (gross) and 340 lb-ft of torque at a low 3,200 rpm.

      Western Sport Special (WSS)

      One unique package was the Western Sport Special. The WSS cars were based on the Challenger Highline, and had small block power, pedal dress up-kit, a vinyl top, and the requisite Western Sport Special Appliqué on the rear quarter panel. These cars were available only to the San Francisco and Los Angeles sales regions, and it was accepted that WSS cars were built at the Los Angeles plant, recently, a handful of 340-powered cars with the documented WSS option were found, having been built at the Hamtramck plant.

      One Challenger Trans Am is known that also had the Western Sport Special badging. The T/A cars had a lot of the pre-existing WSS options (pedal dress-up kit, vinyl top), and it was originally an East Coast car, so it is a very likely story that a dealer installed the WSS decals to move the car off the lot.

      Dodge Challenger Deputy

      The Deputy was a lower priced package, and these cars were very spartan, coming from Hamtramck and Van Nuys devoid of amenities such as air conditioning, power steering or brakes; the JH21 and JL21 Deputies also used base Barracuda seats. Some of the rarest Challengers that year were the 383 3 speed challenger Deputies, with examples numbering in the single digit territory.

      1970 Dodge Challenger SE

      The Special Edition Challenger, JS23 and JS29 for R/Ts, was a separate model, denoted by the second character in the VIN (The Deputies had "L" for low, Highlines had "H"), S for special. The most obvious difference was the "Formal" or smaller rear window, meant to emulate a limousine's back glass. A fiberglass plug was placed over the rear window, and covered up by a vinyl top.

      SE cars had a velour headliner (non-SE cars had a standard headliner, with fabric and bows), and an SE-only overhead consolette, that had warning lights for low fuel and open door. SE and R/T SEs also had leather seating unique to that series, and a "credit-option" of leather seats with fabric inserts. Opting for these seats meant a credit could be utilized towards another option. The Special Edition would be discontinued for the 1971 season, but the vinyl-covered roof with the smaller window would continue as the A78 formal roof option.

      Dodge Challenger R/T and Challenger T/A

      See our separate page on the hot 1970 Dodge Challenger R/T and Challenger T/A.

      1970 Challenger in review

      Beetween the falloff in the market, hot competition from the company's own Duster and Road Runner, and criticism of the cars' dynamics, 1970 Challenger sales were disappointing. There was a tremendous irony there, because two alternative approaches to the same project succeeded wildly, on far smaller budgets.

      The Valiant Charger, Australia's low-budget project which also combined A and B body components, was a wild success, albeit in a smaller market. Valiant Charger may not have worked in the US: the hottest engine was a hemispherical-head, triple-two-barrel carb six. But the other ironic success was a more modest project even than the Valiant Charger: the 1970 Plymouth Duster was merely a fastback Valiant, and with its 340, it was the performance bargain of the year. Challenger and Valiant Charger were both made by combining A and B bodies; Duster was still a pure A-body, with the same semi-formal Valiant front end, yet sales were in the hundreds of thousands.

      Meanwhile, in 1970, Chrysler sold 53,337 standard Challengers; 6,584 SEs; 3,173 convertibles; a bit over 1,000 T/As; and 19,938 R/Ts (including convertibles and SEs). In all, 83,032 Challengers were sold; 60% had the base V8, and nearly 90% had automatics. Styled wheels were more popular than big engines; and the slant six seems to have outsold Hemi and 440 Six-Pack combined, easily. As Burton Bouwkamp wrote:

      ...the compact specialty car market leveled
      off below 1,000,000 cars per year and our E body sales never hit even
      100,000 per year. We lost money (unhappy management) and we did not build
      the cars well (unhappy customers). 1970-1974 Barracudas and Challengers are
      admired and collected today but 35 years ago they were seen as problems..
      And how did the ironic companion to the Challenger/Barracuda fare? Plymouth sold 217,192 Dusters in 1970, their first year. Though Duster fell somewhat in 1971, sales would then rise every year to a peak in 1974 with 250,000 sold (in 1975 and 1976, the Volare/Aspen cut Duster sales dramatically - but even in 1975 it outsold Challenger's peak).

      Dodge Challenger 1970-711973-74
      Width x Height 76.1 x 50.9 76.4 x 50.9
      Track (max) 60.760.7
      Headroom, F/R 37.4 / 35.6* 37.4 / 35.6
      Legroom, F/R 42.3/30.942.3/30.9
      58.1 / 56.8
      Base tiresF70 x 14 (6 x 14)7.35 x 14
      Battery46 amp-hour
      Alternator41 amp41 amp
      Trunk capacity8.6 cubic feet8.6 cubic ft
      318 axle ratio, manual3.23:13.23:1
      318 axle ratio, auto2.76; 3.23 opt2.76; 3.23 opt.
      Curb weight2,970 - 3,336
      * Hardtop headroom: 38.2/36.4; shoulder: 56.2/56.8
      1971 Dodge Challengers

      For 1971, planners looked at the 1970 sales and simplified the range slightly, otherwise largely leaving Challenger and Barracuda intact. They added in the 340 V8, a lightweight but powerful engine that gave serious performance without hurting agility; with the 340 in the line, the U-code 440 four-barrel was dropped. The 383 was detuned to 300 hp and was only available with the R/T; and the 440 Six-Pack was now 5 hp lower.

      The visible changes for were switching from a single tail lamp design ub 1970 to two distinct lights in 1971; and using a new twin-inlet grille, painted silver on standard models and black on R/Ts, which also got fiberglass quarter-panel louvers.

      The slow-selling ragtop R/T was not available, but a few savvy buyers optioned 340 non-R/T hardtops and ragtops with the Go-Wing, Shaker, Rallye Gauge Cluster, and the side stripes that mimiced the R/T versions. The 1971 340 R/T, like 1970's A40 340 performance Challengers (often badged as R/Ts), had a tachometer with a higher redline than their big block bretheren. By the same token, you could order a 340 R/T look-alike with a shaker and a go-wing, and most of the R/T paraphernalia, without the higher insurance premiums.

      The 1971 SE's back window grew to normal size. The Challenger Deputy, a low-cost version with fixed rear side glass and a 198 slant six, joined the base, SE, and R/T models.

      1971 Dodge Challenger pace carSales were dramatically lower in 1971, despite being the Indy 500 pace car - or perhaps because the pace car crashed into the press box. Production was a mere 30,000 units or so, and the R/T - again, the only car to feature the 383 and 440 - sold just 4,630 units.

      The writing was clearly on the wall; the older Charger was easily outselling Challenger, as was Dart Swinger (which cleared 100,000 units in 1971). Over at Plymouth, they sold over 14,000 Road Runners - a dress-up and performance-enhancement package on top of the standard Satellite - as well as 173,592 Dusters (not including 12,886 Duster 340s and over 48,000 similar Scamps). Plymouth wasn't doing much better with their version of the Challenger, a shorter-wheelbase design called the Barracuda: for 1971, they sold fewer than 20,000 of the cars.

      1971 Dodge Challenger T/A: did it exist?

      It appears that the T/A was dropped before model year 1971, but a former factory employee reported that around thirty Challenger Trans Ams were converted from 340 R/Ts (four-barrel version) for the 1971 season, before Dodge pulled out of SCCA. The thirty cars were then converted back to R/Ts.

      To add fuel to the '71 T/A debate, the ad of the Top Banana 1971 T/A in the rain appeared in Motor Trend in late 1970, looking suspiciously like the rainy day ad for a Top Banana 1970 T/A. The reader can draw their own conclusions of the validity of the 1971 T/A's existence. Expert airbrush work (such as the 426 Hemi hood badging in the "No Shrinking Violet" 1970 R/T ragtop ad, an in-violet 383 automatic) was a signature of the advertising department back then.

      1972-1974 Dodge Challengers

      In 1972, there were big changes as a newly struggling Chrysler Corporation dealt with its miscalculations and a failing muscle-car market (failing, among other things, because of the value inherent in the big-engined compacts, and because of rapidly rising insurance premiums).

      A few 1971 Challengers were converted into 1972 convertibles for the T.V. Show "Medical Center" starring Chad Everett.

      The R/T, convertible, and SE vanished, along with the 440 Six-Pack, Hemi, and 383; and the clean grilles of 1970-71 were replaced by the more aggressive "sad faced" grille. The Challenger Rallye was launched to replace all the slow-selling power models of the past. The power leader was now the 240-hp (net) 340, and the 318 (150 hp) was a more realistic base engine than the slant six (which was still around for 1972, but not 1973.) The changes were not enough, or went in the wrong direction, and production was down to just over 26,000 units.

      The sunroof, offered as an option for just over $400, became a popular alternative to the convertible. The larger "egg-crate" grille was painted argent for standard Challengers, and black on the Challenger Rallye model. The Rallye model was also equipped with four small scoops on the front fenders.

      1973 brought huge bumper guards and lost the slant six and gunmetal grey color but gained the new 360 (245 hp net). Production rose to nearly 33,000. As noted, the 318 was now standard, as were vinyl front bucket seats with headrests; a floor-mounted 3-speed manual transmission; front and rear ashtrays; heater/defroster; day/night mirror; concealed two-speed wipers; dual horns; various mouldings; and energy-absorbing steering column. Those who wanted a passenger side mirror had to pay for it.

      In 1974, there were two engine choices: the 318 and somewhat more powerful 360, which was only available in 1974; it replaced the 340, which ended in 1973. The lap and shoulder belts were equipped with an inertial reel. A generally disliked, single-year feature was the federally mandated seatbelt-ignition interlock. Production was a mere 16,000 units.

      Challenger production ceased in 1974, a choked incarnation of what ruled Woodward Avenue in the early part of that decade. The name was resurrected in the late seventies for a Mitsubishi built compact; and in 2008 for a visual clone of the original, the new Dodge Challenger. Ironically, the new version sales seemed to hover around those of the 1971 Challenger.

      1970-74 Dodge Challenger retrospective

      In its short life, the Challenger turned out to be one of the best-looking cars produced in the muscle era, and is today highly sought after. A 1970 Challenger R/T starred in the film Vanishing Point, a high-speed pursuit movie that has become a cult favorite among muscle car fans. 1970 Dodge Challengers also made appearances on the big screen, in movies such as Used Cars, Natural Born Killers, and Phantasm I and II. They were also seen in television shows such as The Mod Squad.

      Challenger sales were never satisfying for Chrysler, which had invested quite a bit in the Challenger and Barracuda - rather than in the A-body. Buyers found the interior space to be small for what was a fairly large car, critics slammed the handling, and the muscle-car market dried up rapidly with insurance company premium hikes and, later, gas shortages. The car had far too much overlap with Chrysler's existing cars - the Charger, Road Runner/Super Bee, and Duster/Demon. It seems that Chrysler could have simply restyled its existing B-body line to much better advantage; it would then have extra money to invest in A-body variants or even a replacement for the already-aging A-body line.

      Approximately 188,600 Dodge Challengers were sold over its lifespan.

      Dodge Challengers versus the competition

      The chart below is from 1972, so horsepower figures are net, not gross (as in the chart above).

      1972 figuresDodge ChallengerFord MustangChevrolet CamaroAMC JavelinPlymouth Duster
      Front headroom37.437.237.437.537.5
      Rear headroom35.636.036.135.636.5
      Front legroom42.341.843.842.541.5
      Rear legroom30.928.230.730.829.9
      Trunk space (cf)
      Base Six hp/torque110/18599/184110/185100/185110/185
      Base V8 hp/torque150/260141/242130/230150/245150/260
      Brake swept area314267337255/267254.5 / 251.4
      Lube interval36,00036,0006,00024,00036,000
      Rare Dodge Challengers

      A plethora of options could safely make no two Challengers alike; for example, a 318 Challenger was special-ordered in DY3 Cream, with a Red Vinyl top!

      In the spring of 1970, Gator Grain vinyl tops, with a texture mimicing an alligator's skin, appeared on the option sheet, as well as flourescent green and Panther Pink longitudal tape stripes. What really set those stripes apart was 3M's reflective technology; at night, they would reflect direct light, as street signs do. Many unique possibilities were available in cars built by Chrysler.

      The Diamante show car was constructed from a Challenger Convertible, but that wasn't the only custom-bodied Challenger built. Taking a cue from Sergio Scaglietti's rebodied Corvettes of the late fifties, Pietro Frua constructed a one off "Challenger Special" for a Swiss businessman in 1970. Starting with a R/T SE, and with styling rivaling Paninfarina's best offerings, the car had Borranni wire wheels, a 440 4 barrel/727 automatic, and an interior that was unmistakingly Dodge Challenger.

      That wasn't the only Dodge E-body in the European Union. Chrysler at the time owned the French car maker SIMCA, and around 200 partially completed white cars made the journey up the St. Lawrence Seaway, and on to final production in France, because shipping without headlights and a few trim pieces evaded the tax laws. The most obvious differences were speedometers in metric, which leaves this author to wonder if the odometers were geared for miles and kilometers; clear parking lamps/turn signals as opposed to amber; and door-mounted rear view mirrors manufactured by Talbot, of Talbot-Lago fame. Other European Challengers had special turn signal stalks with a button at the end to actuate all four headlamps, for passing that pesky slow-moving Porsche on the Autobahn.

      Other noteworthy Challengers are the R/T SEs specially ordered by Dandy Dick Landy. Covered in an Iridescent Silver Metallic from the Imperial's pallette, it would be months before a short-lived silver was available, and a whole model year before GA4 Light Gunmetal Metallic would appear on the order books.

      More homegrown customs include the handful of 1971 Challengers that got '72 noses and tails for Paramount Picture studios, after the demise of the convertibles from dealership floors in the 1971 season. Chad Everett always raced to the hospital just in the nick of time in a pretty '72 ragtop.

      The Indianapolis 500 that year was marked by disaster on the opening lap with the destruction of a red ragtop pacing the event. Eldon Palmer, a local dealer, misjudged the car's braking ablity going into a turn. The car was subsequently repaired, and others took its place to finish pacing duties. Replicas were available at local dealerships around the Indianapolis Metropolitan area. [Challenger pace car]

      Some 1970 Dodge Challenger Accessory Groups

      C H A L L E N G E R B O O K S

      E N G I N E B O O K S

      Chrysler 1904-2018

      Spread the word via <!--Tweet or--> Facebook!

      We make no guarantees regarding validity or accuracy of information, predictions, or advice - .
      Copyright © VerticalScope Inc. All rights reserved. Dodge, Jeep, Chrysler, Ram, and Mopar are trademarks of Fiat Chrysler Automobiles.

    1. · Premium Member
      3,295 Posts
      1970 Dodge Challenger R/T and Challenger T/A

      1970 Dodge Challenger T/A

      by Kelly Doke

      In May 1969, a Chrysler product planner conceived the Dodge Challenger T/A; it was born nine months later, on February 12, 1970, and issued a "birth certificate" (Technical Service Bulletin 11). Pontiac had Trans Ams prowling the streets, so the name had to be shortened, but the car was created to run in the SCCA Trans America series, so the T/A name was justified.

      The T/A was created because automakers had to make actual retail cars to compete in some motorsports; just as they had to make real Charger Daytonas to run the supercars in NASCAR, Dodge had to make 2,400 Challengers T/As for civilians to support one SCCA racing car.

      In accordance with the Sports Car Club of America rulings, Sam Posey's #77 Classic Wax Challenger started life as a Body-In-White, meaning it was a street car that was delivered to a racing group with a unibody structure, and little else. #77 was painted FJ5 Sublime, and at first, the massive amounts of green were overpowering. Longitudal black R/T side-stripes and a black vinyl top were applied to offer visual contrast.

      The vinyl top was purported to increase structural integrity, as the Body in White was acid dipped to cut weight; and according to one report, a team member leaned on the roof during a qualifying race, and put a massive dent in the racer's roof. A Challenger from a local dealer's lot donated its normal roof, and Sam Posey went on to qualify the next day. Keith Black, of Hemi drag racing fame, built the 303.8 cubic inch LA-based motor that occupied the gloss grey engine compartment.

      Sam Posey drove the lone Trans Am racing Challenger in 1970. Drag races Dick Landy and Ted Spehar also campaigned Challengers in the National Hot Rod Association's new Pro Stock class.

      The T/A cars that ruled the streets were a different animal altogether. Starting with a Challenger Highline (JH23), the A53 Trans Am package had a special 290 horsepower 340. Carrying a unique "J" VIN prefix, the engine had increased webbing in the mains, valvetrain revisions, and the ubiquitous trio of troublesome Holleys residing on an Edelbrock intake manifold.

      The coveted Challenger Trans Am was based on the Highline, and unlike the big-motor R/T or the Luxurious Special Edition, it was not a separate trim level, but a package available on a pre-existing model.

      The A53 cars had unique spoilers front and rear, the N94 Fiberglass hood (the Pilot T/A has a regular R/T dual snorkel hood), and Hemi fenders up front to house the fat F60 series Polyglas up front. On many of these Challengers, fiberglass hood was lifted off (no hinges), and the flat black color and fender pins gave the car a unique look. (Wendell Lane wrote: "my 1970 Challenger T/A had hood hinges, with lighter hood springs for the fiberglass hood, and dual hood pins up front.")

      Out back, the cars had increased camber in the rear, and G60 tires. The antenna mast was relocated to the rear passenger quarter panel, in the belief that the lack of a steel hood impeded radio reception. The cars carried suspensions from the Hemi and 440 Six-Pack cars: the K-frame with a skid plate, thicker torsion bars and sway bars, front and rear, 3/8 fuel lines, torque boxes welded to the unibody just ahead of the rear leaf springs (the passenger's side has an extra half-leaf, like the Hemi and Six Pack cars did). The T/A cars had a fast ratio steering box as well, along with differently sized front and rear tires, and increased rear spring camber. They could do the quarter mile in 14 seconds.

      The T/As had unique striping that extended the character line of the leading edge of the C-pillar, and terminated just before the front fender trim at the front of the car. The manual 3-speed was not available, nor was a bench seat, and the only wheel options were black steel wheels with dog dish hubcaps and trim rings or the Rallye wheels. The passenger side front fender is completely unique to the T/A: it has a rolled wheel well lip like the Hemi Cars did (Hemis had 15" wheels), but no provision for the radio antenna. The T/As also carried unique exhaust (California models included) whose tips peeked out just in front of the rear wheels. Concours restorers should note that few examples had these unique mufflers (exit and exhaust on the same end) painted black, depending on the vendor.

      989 automatic and 1,411 four speed T/As were completed from late March to mid-April 1970. While the T/As were pretty much optioned alike, the rarest of those rare breed would be the lone Western Sport Special, which again, may be just a few stickers applied to a slow moving car. The rarest T/A known to be legitimate would be the one with a factory sunroof.

      William Fayling wrote: "I have had the pleasure of seeing the first one built and it has T/A striping, fiberglass hood (single scoop), rear and front spoilers."

      1970 Dodge Challenger R/T

      The Challenger R/T cemented the car's image in the hearts and minds of fans: a snorting big block, tape stripes, and the Shaker hood all made the car memorable. In 1970, the R/T package started with the 383 four barrel. Carrying a separate JH27 VIN prefix, single digit gas mileage, and neck snapping performance, the Challenger made its mark on Woodward Avenue.

      Dodge Challenger 1970-711973
      Width x Height 76.1 x 50.9 76.4 x 50.9
      Track (max) 60.760.7
      Headroom, F/R 37.4 / 35.6* 37.4 / 35.6
      Legroom, F/R 42.3/30.942.3/30.9
      Battery / Alternator 280 / 41 amp
      Trunk capacity 8.6 cubic ft
      * Hardtop headroom: 38.2 / 36.4; shoulder room: 56.2 / 56.8

      The most coveted of the R/T lineup was the 426 Hemi, rated at 425 Horsepower, and its sibling the 440 Six barrel, rated at 390 horsepower. The "R" code Hemi and the "V" code Six pack also carried a laundry list of architectural tweaks in the body structure that differentiated it from the lower performance E-bodies. For starters, both cars did not have air conditioning. Ever.

      The R/T's base 383 cubic inch engine, putting out 335 gross horsepower, was potent; options were the legendary Hemi (425 hp but only 356 buyers), the more affordable 440 Magnum (375 hp with a single four-barrel carb), and the Hemi-challenging 440 Six Pack, with three two-barrel carburetors (sold to over 2,000 people, and featuring 390 gross hp and a stunning 480 lb-ft of torque at a low 2,300 rpm).

      While the R/T had a standard dual-scoop hood, the functional scoops simply pushed air into the engine bay, rather than forcing it into the engine; for that, you needed the "shaker" hood, which was essentially an attachment to the air cleaner that protruded through the hood.

      The K-frame had an additional skid plate added to the bottom. The cars had thicker torsion bars, 3/8" fuel lines, and structural reinforcements to the floor around the pinion snubber area. Immediately recognizable is the "torque boxes", shared with the convertibles, which were situated just ahead of the rear leaf spring perches, underneath the rear seat area. Forming a square shape, they reinforced the rocker area with the rear frame rails, and after years of having jack pads and the weight of the car sandwiching them, they suffered lots of beating since leaving the factory. Also of note, most of these cars had the Dana 60 rear end, with an extra half-leaf on the passenger's side to counter the torque produced by these engines.

      Hemi cars also carried unique front fenders, due to the 15" wheel option. What made the fenders unique were that the wheel well openings were rolled more than the 14" wheeled siblings to accommodate the larger wheels. (All Challengers had a 110" wheelbase.)

      A heavy duty TorqueFlite 727 automatic transmission was standard on the 440s and Hemi engines, with a four-speed manual optional; the common wisdom was that the TorqueFlite could outrun the manual, despite the latter's Hurst pistol-grip shifter and Dana 60 rear axle. A limited slip differential was optional, but a heavy duty suspension was standard across the R/T line. Even the Hemi was restricted to 15-inch 60-series tires, which today are reserved to base model economy cars.

      While the R/T had a standard dual-scoop hood, the functional scoops simply pushed air into the engine bay, rather than forcing it into the engine; for that, you need the "shaker" hood, which was essentially an attachment to the air cleaner that protruded through the hood.

      For 1970, Dodge sold 53,337 standard Challengers; 6,584 SEs; 3,173 convertibles; a bit over 1,000 T/As; and 19,938 R/Ts (including convertibles and SEs). In all, 83,032 Challengers were sold; 60% had the base V8, and nearly 90% had automatics. Styled wheels were actually more popular than big engines; and the slant six seems to have outsold Hemi and 440 Six-Pack combined, easily.

      The original Dodge Challenger Trans-Am 340 Product Planning letters

      2009 Dodge Challenger | Challenge Creation Stories | Plymouth Barracuda | Forum

      C H A L L E N G E R B O O K S

      E N G I N E B O O K S

      (Note: all prices above are correct at time of publication to the best of our knowledge. Final pricing will be set by when you order.)

      Chrysler 1904-2018

      Spread the word via <!--Tweet or--> Facebook!

      We make no guarantees regarding validity or accuracy of information, predictions, or advice - .
      Copyright © VerticalScope Inc. All rights reserved. Dodge, Jeep, Chrysler, Ram, and Mopar are trademarks of Fiat Chrysler Automobiles.

    1. · Premium Member
      3,295 Posts
      Mopar 2.2 and 2.5 TBI Power Upgrades

      Neither Allpar nor any of the contributors take any responsibility for the results of your actions or for the results of following the steps or advice presented below. Some of these may shorten the lifespan of your car and/or its components.

      The TBI engine is essentially any 2.2 or 2.5 with a single fuel injector. These engines were used on many cars, minivans, and light trucks. The computers and the engines underwent many changes as the years went on.

      Turbocharged engines had multiple-port fuel injection (each cylinder had its own injector), but the TBI models had only one, which is less efficient. David Zepeda pointed out that in Mexico, the 2.5 was given multiple port injection, boosting power.

      Modifications to Chrysler/Dodge/Plymouth 2.2 and 2.5 liter TBI engines

      There isn't much you can do to increase performance a TBI engine, and the following modifications may not affect your performance too much. Adding a turbocharger is rather extreme but works, as does selling the car and buying a turbo model.

      The 2.2/2.5 TBI engines were competitive when they were made. These engines have nice low-end torque for four-cylinders but have issues with breathing and fuel supplies.

      by Edward Kelly

      For substantial money you could have the head ported, with port matching of the manifolds. Back cutting the valves and 3-angle valve job will both help the head flow better especially at low valve lift. The valve guides are probably worn, you can have them replaced or spiraled to bring them back into tolerance; new valve guides will last longer. Spiraling is cheaper.

      Porting is probably the most costly intervention. Shaving the head to up the compression ratio would also increase hp. If you shave it too much you will need to run an oversized timing belt tensioner or an undersized belt (both sold by Mopar Performance). You may also need to run higher octane fuel. If you decide you don't like the increase compression, you can get a copper shim gasket (Felpro makes one) to move the compression back to stock.

      Degreeing the cam will also help.

      by Derek Beland

      The problem with tweaking TBIs is that very few changes are individually noticeable. Most mods you can make will yield an increase in power that is a factor of the baseline power from the factory. Since factory power is around 93-100 hp, gains come in 2-5hp increases. Some ideas are:

      • advance ignition timing to 15 degrees
      • play with cam timing via offset keys
      • remove intake elbow
      • remove heated air flap in airbox inlet (this will hurt drivability and emissions)
      • hotter coil, wider plug gap
      • remove coolant lines to throttle body (the latter may hurt drivability)
      • bore out throttle body
      • modify the butterfly (shave shaft, shorten screws, knife edge leading side)

      The expensive/time consuming stuff:

      • ported head
      • bigger valves
      • convert to carbs (may be against the law or cause emissions test failure; may hurt gas mileage; may hurt drivability)
      • shave head to raise compression

      This assumes of course that your engine is in top running shape. A compression test might be wise, and potentially a ring-job. These mods may cause you to run lean so you will ned to get an air fuel meter when you start.

      There are differences between the later model TBIs and early ones. My stock fuel pressure is 39 psi, so I'm sure the injector is a different flow rate as well. My head has the "TS" stamp on it, which Gary's website says indicates a turbo head - but this one is definitely the original. Perhaps flow is better. I know the intake manifolds for later models are slightly different. There was a TSB about hard starting that indicated the manifold could be switched to a later revision to cure the problem.

      Most people have to mod what they have. I don't think it's unreasonable to think you can get another 20-30hp out of the motor, with a reasonable budget.

      I like my MSD6A ignition system. The cars pulls to redline at a steady speed, vs running out of steam at the higher RPMs. I have my car set up so that I can bypass the MSD and run straight to the coil, and there is a small but noticeable difference. Is it worth the $200 price tag? That's subjective. You need to mate it with a Blaster 2 coil.

      Lots of people say they've had problems with the MSD breaking down. I had one Blaster coil die on me, an interior connection snapped off. Because my coil is mounted on the thermostat and thus subject to a lot of vibration, I switched to the "High Vibration" version (filled solid with resin) and haven't had a problem since. I've had the MSD setup in the car going on five years now, 3.5 on the new coil. I mounted the MSD with rubber isolators, so maybe these people were screwing them down solid to the frames/fenders and they got shaken to death?

      Timothy Pindell

      I took my Daytona to the Nationals for a few passes. The car is now capable of mid 17s with a good reaction time. Here's what I did to mine:

      1. Mopar Performance camshaft P4529320 252/252 duration, 36 overlap, 108 centerline, (uses factory .430 lift)
      2. Cam installed "straight up" with the help of the offset keys
      3. Accell super coil, .05 gap on the Champions
      4. Ignition timing set to 15 advance
      5. Fuel pressure raised to 15.5 psi (it idles poorly)
      6. Removed rear seat, spare, jack
      7. 2 gallons fuel
      8. Removed AC and PS belts
      9. Rear tires to 55 psi, fronts to 35
      10. Removed air filter, left the box
      11. Dynomax muffler/ 2.25 exhaust from the manifold/ no catalytic converter (it's rather loud with a straight-pipe edge to it)

      I shifted at 6200 (indicated) rpm. It was still pulling, but not much.

      This illustrates my belief that you can't get much out of a TBI unless you get radical. It's got a bit more than what it had when it left the factory, but not as much as the turbo guys get for the same effort. Don't teach a TBI to go real fast. It wastes your time, and annoys the engine.

      Summary of low-buck approach

      David Reynolds wrote: "the best performance you can get from a 2.2L TBI car is to be had by (in order of expense):

      • advancing ignition timing to 14-15 degrees (free)
      • K&N drop-in filter ($35)
      • 2.25" exhaust (around $100)
      • raise compression *a little* by shaving the head and/or block (expensive)

      I have done all of this to my Sundance, and I have very good drivability for a 2.2 non-turbo. I am also using a Comp Cams camshaft, but I'm not convinced it makes a big difference over the stock cam. For an '87 or earlier slider cam, though, you may want to consider switching to an '88 or later roller cam. Switching cams is actually a fairly easy thing to do yourself, and you can usually get a used one pretty cheap.

      Note that the changes I made to my Sundance require 93+ octane and raised fuel pressure to keep it from knocking. I raised the fuel pressure by squeezing the regulator in a vise (a la Gus) a little at a time, then testing to see if the knocking improved.

      All of this taken together has given me a strong power band between about 2000-3400 rpm, which is great for my city driving to and from work. It has next to no top end, though.

      2.2 / 2.5 TBI breathing


      Dan Stern wrote: A Magnaflow (similar to an Ultra-Flo) muffler and low-restriction catalyst perceptibly helped.

      Bradley Miller suggested: "Daytona/Laser mufflers will fit our cars. Stock pipe is 1 7/8". Lambros Race Engineering has an adjustable fuel pressure regulator that will allow for fixing lean conditions. They also have different gear ratios (provided you don't mind losing top end) and they have different pulleys. This will spin the accessories a little slower to reduce parasitic horsepower losses. The exhaust helped with the sound of the car and the mid-range pull. I've now got 2 1/4" pipe all the way back to a Walker Super Turbo muffler. You can step down on the accelerator and really get a good shove in the pants without the car downshifting. In the upper RPM bands it doesn't really help too much."

      Derek Beland wrote:

      I have the Super Turbo on my 92 Daytona 2.5L NA (TBI). Sounds really nice. I lost some grunt on the low end, but the high end is slightly improved. I had Midas fabricate a 2" pipe (stock is 1 7/8") pipe from the cat back into the muffler, which is 2 1/4" in/out. It's significantly louder, but not annoyingly so. Make sure the install is good and the tailpipe exits past the bumper (it'll need a bend to do it, a pipe straight out from the muffler would hit the rear bumper). Mine is too short, and above 3000rpm I get a booming resonance inside the cabin. My stock exhaust was leaking in about three places, so I took advantage of that and replaced it with a performance exhaust.
      Muffler replacement instructions, tips, and stories

      Jerry Adams warned:

      I have used K&N oil-wetted gauze air filter on several vehicles - some carbed and some injected. They do flow more freely than paper. However, their usefulness stops there in my experience. When I inspected each one before I installed it, I wondered at the light I could see through holes in the gauze! Every one of the intakes got very dirty downstream from the filter. Partly due to oil that was carried by the air and caught on the side of the intake or carb and partly due to dirt that got through the K&N filter.

      So I went looking for a substitute that would flow freely and be very efficient at stopping the abrasive particles. I found several oiled foam air filters - HKS Super Mega Flow, Amsoil, Finer Filter, Dura-Blue and Accel. I reviewed the available test data which showed K&N flows more air and more dirt than paper - as I suspected. It also showed the oil foam flows more air than paper and almost equal to K&N - except K&N's data showed their filter best.

      If you drag race, K&N is probably okay, but I will not use them on the street again. If money is no object, you could use the K&N with the K&N Pre-Cleaner - a oiled foam cover for the cylindrical K&Ns. It seems even K&N knows their filter needs help so they sell it!
      Bradley Miller wrote: "I did all the bolt-ons I could within reason on my Duster and didn't see any neglible improvements. Going from 100 to 110 hp in a 2900 lb. car . . . well you get the picture."

      Intake manifold

      Dan Stern said there was an updated intake manifold to solve the long crank time on cold starting. Joe Pfeiffer also suggested replacing the intake. Vincent Cheng described reworking the intake manifold:

      Use a high speed hand grinder and smooth out the plenum and runners. Round off all sharp turns. Rounding off the edges and enlarging and smoothing the inside contours of the runners can add breathing efficiency without any notable sacrifice in other area. (From "Performance with Economy" by David Vizard).
      Air filters and related stuff

      Bradley Miller said:

      • Between the headlight and the battery there will be a little plastic "bucket" that's supposed to keep snow/debris from going up the intake hose to the air cleaner. Pull this off. Smooth pipe from the airbox to the air duct by the battery will also help. Do not remove the hose. This hose pulls air across the drive transistors for the injector. Without this hose, you WILL burn out the transistors. [Note: one EEK! member took off the hose but added a fan to blow air onto the transistors. Others, including Gus McMahon, have been running for years without it, and suggested that the airflow was probably only needed in desert areas or during extreme heat. Jeff Chojnacki wrote that he has been doing without computer cooling since 1989.]

        Cut a hole (about 3" dia.) in back of air box. This is supposed to give you a little bit more low end torque. Make sure to put a mesh up there to keep large objects out of the air box. OR - Change the airbox altogether. (Webmaster's warning: cutting the hole in the back of the air box will delay warming, especially in cold weather, because it bypasses the stove. The best way to do this would be to have a control, like a manual choke, where you can shut it off or turn it on from inside the car; if you like electrical stuff you might even be able to fit a solenoid in there somehow. I do not suggest cutting the straight hole for most people who live in "normal" climates. Those who are in very hot climates, e.g. South America, may be able to get away with it more easily. A cold engine has lower fuel economy and power, higher emissions, and shorter life).

      Martin Rempel wrote:

      Before my turbo van I had a 89 Spirit TBI. One of the things I did was pick up a throttle body (TB) off of a wrecked car and had it bored out. There is not a whole lot of material to bore out. There are two very small vacuum ports that are in the bowl area. These tend to open up as you bore it out. I had a larger throttle plate made and had the TB on the car for a while. It made some difference but not much. I still have the bored out bottom half of the TB if you want it. The throttle plate I made was not quite big enough so my idle went up about 2-300 rpm. According to Gary Donovan, the major problem is the intake. Check out his site for more insight. He recently completed the TBI database.


      The general consensus is that the stock ignition system works well enough for most purposes - unless you really hot-rod the engine, which as you noticed we do not recommend (given the effectiveness of a turbo-swap).

      Mike King wrote that overgapping the spark plugs to .040", rather than the stock .035", helped in power. This had also come up in the EEK mailing list several years ago. The consensus was that Chrysler tended to be conservative in plug gap - other makers have larger gaps. Mike said that the power boost was stronger when coupled with midgrade gas. Note that this increases the strain on the ignition system, but that others have reported no problems.


      Dan Stern wrote: Most of the TBI cars came with a final-drive ratio of 2.78. This is great for cruising at 75 mph all day, but around-town the engine is working below its torque peak and straining against the low-stall torque converter together with the high final drive ratio. This is also why early Slant-6/auto Darts feel peppy, while later cars feel "mushy" and slow --the early A-bodies have 3.23 or 2.93 gearing, while the later cars have 2.76s (and even later cars got 2.45s and 2.26s!). There was also a 3.22 ratio available for this A413 3 speed auto used with the 2.2 and 2.5 engines.

      Sensors and stuff

      Some advise a lower-temperature thermostat (e.g. 180 degree) - this is fine if you want to pollute more and lower your gas mileage, but is not really a sensible way to run your car. The engine was designed to have a certain amount of heat.

      Fuel injection

      Herb DaSilva: "If you start to get lean, get in touch with some of the companies that specialize in fuel injectors and get an 8% or 10% oversize injector. The stock computer will be able to handle it." (This is if you make other power modifications which cause the stock injector to be unable to handle the load.) Conversion to multiple port fuel injection is generally considered more trouble than swapping in a turbo engine.

      Bradley_W._Miller wrote: "we have the little blue bottle. (NOS) The ultimate equalizer. A system runs under $400, depending on where you get it. An extra 50-75 hp is about the safe limits, with stock parts. You just have to be careful to keep adequate fuel pressure and not to use it at too low of an RPM. Dropping 2 seconds off your ET with one of these is no problem."


      Stefan Mullikan wrote: Pierce Manifolds sells the side draft Weber kits [that fit the 2.2 and 2.5 engines[ as well as the manifolds for our 2.2/2.5 motors. The complete side draft Weber kit from Pierce is $823.20. The side draft Weber manifolds, is $293.24 They can be reached at:

      Pierce Manifolds
      321 Kishmura Dr.
      Gilroy, CA 95020

      Camshafts and balance shafts

      Taking out the balance shafts from the 2.5 engine is said to provide a very small power gain at the expense of smooth idling.

      Gus Thomas wrote: The rumor of increased performance from disconnecting the balance shafts in the 2.5 engine is the result of a tech article by a Chrysler engineer a few years ago. It was re-written by Gary Donovan last year, and put in the SDAC newsletter. He said that 14 HP is gained at 6,000 rpm. How long are you at 6,000 rpm? For less than 1/10 of one percent of your engine's life? You're sure not gonna feel that 14 HP much!

      Because frictional losses increase as the square of the increase of rpm, at 3,000 rpm (a real-world everyday rpm) you only gain 3.74 hp (the square root of 14). That's difficult to feel in the seat of your pants. I do it anyway (remove them) because I get slightly better gas mileage, don't whip up the oil as much, and get a little edge when I am at 6,000 rpm at the track. When you're heading into the 11s with a 2,770 lb Acclaim, you need every bit of free help.

      åHerb DaSilva suggested that 2.5 owners get a Mopar Performance cam and getting underdrive pulleys from LRE (Lambros) or others.

      Bradley W. Miller wrote:

      A Purple cam shaft for the 2.2 TBI will work on the 2.5s. There are two different numbers, one for automatics and one for 5 speeds. Lambros does porting and other head work. Lambrose is real good to work with.

      New cam would improve bottom end with top horsepower about the same ([according to] Forward Motion).

      Here's the price and part numbers of the camshafts - P4529321 - Manual $89.25 (List $119) P4529319 - Automatic $89.25 (List $119) (1996 figures)

      Here's the bio from Forward Motion: RPM Range 2800-5800 (2500-5500 on automatic). Best choice for those looking for more midrange and top end horsepower. Really likes a ported cylinder head but it will work well on stock. Excellent Nitrous Oxide camshaft with Stage. 2 head. We have run 13.80's @ 107 mph with this piece.

      Note that those prices are probably about the same that you can get it through a local Dodge dealer by whipping out your Shelby Dodge club card. About a 25% discount on parts.
      John Basol wrote:

      Competition Cams has a cam for the 2.2L the has 260 degree duration and a .460" lift. produces a power band of 1200-5000 rpm. That's what I need, the best of both worlds. The slightly higher lift to improve low end torque without the loss of high end power, and the slightly longer duration to increase high end horsepower without sacrificing low end torque. With a power band that wide I'll be smoking turbos not only off the line, but even after I shift it will drop right back into the powerband. Cost of the wondrous wand of steel: only $128. I don't think miracles come much cheaper than that!

      I do believe the cam that I found will also work in a 2.5, provided it isn't a turbo. Our stock cams are the same (part no. and all). As for why the factory did not use this type: all of the cams they have designed have been for race use. In drag and track the long duration short lift provides the power in the high rpm range. In rally racing the cams that they have designed for that purpose provide the torque required. They apparently didn't see a market for modified street use. The cam I found being both high lift and longer duration will require me to use the heavier springs from Mopar. This is due to the "lumpiness" of the cam. It should however maintain the correct idle for the motor. Competition Cams' part number for this particular cam is 22-123-4. They can be reached at 1-800-238-0341. Direct from Comp. Cams it runs $128.73.

      1. High Energy
        Powerband: 1200-5000 RPM22-123-4
        Powerband: 1500-5200 RPM22-127-4
        Powerband: 1800-5500 RPM22-131-4
        Powerband: 3000-6000 RPM22-124-4

      Dale W. Kentoph wrote about 2.5 TBI performance upgrades, and his progress on his own 1988 Dodge Daytona:

      I purchased a spare cylinder head and ported it myself. The only problem was, I didn't do a valve job on it, and it had sticky valves. Thus I ran the stock head for the summer.

      I installed a Comp Cams cam, part number 22-127-4. This was total experimentation, as this was one stage up from the one John Basol wrote about, and I wasn't sure it would work with the stock computer. I had to advance the timing a bunch (by ear), but it works pretty well. The power band is 1500 to 5200, and it doesn't have the torque of the Mopar cam I had before, but the power stays about the same clear past 5000.

      I had the head shaved .015, added a K&N air filter, a high output coil, and a mildly over-rich fuel injector.

      It really runs up through the revs easily. As an extra benefit, my mileage improved by about 2 mpg.

      I almost forgot, I had two and a quarter inch pipe installed, along with a turbo muffler. The bigger exhaust actually quieted it at the low and medium rpms.

      I found that the service manager at the Hibbing Chrysler Center, located about 30 miles from me, knows a lot about 4 cylinder performance. He told me a lot of interesting things. He says that .020 is about the limit on head milling gor running street gas. He also said that a Shelby computer limits the total advance to 38 degrees instead of almost 50 for the stock computer.

      This winter I will get a valve job done to my ported head. Next spring I plan on trying to get a set of headers on it too, and hopefully a Shelby distributor.
      Many people have had success with simply advancing their cam timing, which can raise gas mileage and power. Click here for instructions.

      Match porting

      Vincent Cheng wrote:

      1. Use 80 grit sanding rolls for this job. First start by applying dye to the intake gasket surface of the head. Fit studs into the head to help position the intake gasket during the next step. Carefully slip the intake manifold gasket over the studs and against the head so it most nearly matches the intake ports of the head. Working carefully so the gasket isn't moved, scribe a line around each intake port, following the inside diameter the gasket hole. Do the same on the intake manifold. Use bolts to locate the gasket in place. Remove gasket and set it aside.

        Next, with a carbide cutter, grind away the intake port and manifold to match the lines scribed on the mating surfaces. Dip the cutter in beeswax or kerosene to prevent clogging. Blend the new contour into the intake port about one to two inches. Then, you can streamline the valve guide boss, don't remove much material from the guide for fear of weakening it. Remove just enough metal to blend the guide into the port walls.

        After that, with a carbide cutter, carefully and slowly taper the port so that the surface is smooth where the valve seat and the port meet. As you smooth the passage, be very careful not to nick the valve seating surface. The object here is not to remove a lot of material but to eliminate any ridge between the head and seat. Blend and smooth the rough cut into the port wall. Don't take off a lot of material here: Grinding excessively may actually reduce flow! Then, surface the port using the sanding rolls. Don't try for a mirror polish, since a slightly rough finish will be best compromise between flow and fuel atomization.

        Repeat the procedure for each exhaust port, being careful not to enlarge the exhaust port more than the size of the exhaust manifold. Lastly, finish the exhaust port surface with fine paper (220 to 300 grit). A mirror polish in the exhaust port is desirable because it reduces carbon buildup. This is from the Toyota Performance Handbook by Pat Barden.
      TBI to Turbo

      Maurice Barrett wrote:

      I would stick with the stock rods, less reciprocating mass, better throttle response. Early T1's and 2.2 TBI both used light weight rods and I don't see why you would need anything else if you are not going to push more than 200hp.

      (Responding to the question of using forged or cast pistons) Neat little trick I heard from a turbo dodge friend, was on 88 Tall Deck TBI 2.5L's you can use early flat top 2.2 pistons. This would kill two birds with one stone, higher compression, beefier first ring land.

      (On using Weber side-draft induction)

      Totally agree, or you could even go fuel injected and run a turbo intake and batch fire all 4 injectors off a TBI computer (Check out the page on Dereks site). Just as long as you ditch the TBI or carb manifold (heard carb manifold flows better than TBI, but I doubt it compares to side drafts or a 1 piece turbo intake).

      (On a $3,000 cost estimate)

      You can probably cut some off that 3000 predicted total and still build a engine the right way. The engine you are describing sounds like overkill in some aspects for a NA engine

      The great thing about Chrysler is they like to use parts which are usually never pushed their potential in stock form. Find the right combination of parts and you can build a nice little engine.
      Timothy Prindell wrote back:

      I totally agree regarding the point on increased throttle response and recip mass. Here's my logic behind me and the later rods: It's not the power output I'm worried about, it's the RPM needed to make it. The NA engine is going to need to turn some rather serious RPM to get to 200hp. This RPM increases piston speeds and the need for increased strength to stop and start that piston. The late turbo floater rods wiegh 40g more than the early T1 rods and only 8 more grams per each than the early carbed rods (5203384). I guess it depends on the individual comfort level. If I had the heavier rods on-hand, I'd probably use them if I weren't going to build a turbo motor.

      (On the cost): I agree. Some of it is overkill. Some machine work isn't exactly required, but I make sure I at least get the block, crank, rods and head checked and cleaned up. That adds up quick. I overbuild my shortblocks and suggest that to other enthusiasts. The rest can be easily modified later without pulling the engine. Build a great platform, and it doesn't matter what I do later. I know it'll handle it. Don't skimp on the machine work tho. That can bite you later.
      Some suspension notes

      Stefan P. Mullikin wrote this guide to Shelby Daytona springs and EEK / Daytona suspensions in general:

      The front Koni's have 5 (?) adjustment settings and are accessible from the top with a small screw driver. The rear unfortunately are only adjustable by compressing the strut and turning the housing. Generally I find that you don't need to adjust them very much as the middle setting seems pretty good all around. For track days and the like, just adjust them up while you're performing the typical routine maintenance one would do before hitting the track (checking for loose items, broken wiring, leaks, bleeding brakes, changing oil, etc)

      You can probably "fix" the height difference front to rear with some spacers on the rear springs. Not ideal, but easier than adding jack screws to the rear perches (similar to NASCAR racers since their spring setup is similar to ours as its separate from the shock)

      The Shadows, Daytonas, Lebarons, Lancers, etc share their suspension with the K-car so they can all use the same struts, springs, sway bars, cross members, etc. So the spring's measurements should be similar. The differences being free length and wire diameter (which determines height and stiffness) If you search the archives you'll might find the actual rates of the Eibach spring kits. I do know that the Shadow kit has a higher rate spring (280lb/in on the front if I remember correctly) Not sure of the free length difference between the two of them.

      Independent rear suspension for the K-car would be plausible, but the gains would be unknown as the real issue is really with the front. Horrible camber curves, binding sway bars and control arm bushings, bump steer, lots of soft rubber to eliminate any hope of maintaining what little geometry you have, etc. The later model k-members help alleviate some of that, but it's still a strut front end and it will always have that as its main Achilles heal.

      The best things you can do is to eliminate the bump steer with rack spacers. Reduce the sway bar's binding by either running a Quickor end link bar (better but not perfect) or running a custom unit that is mounted to the front core support. The idea is that the sway bar is only active during chassis roll, not during bounce or rebound (i.e. it would be nice to be able to move the control arms by hand with or without the sway bar attached)

      Once the above has been done, the car won't pull much more lateral grip than before, but it will be much more repeatable. So when you turn into a corner, you should be able to the set the wheel into position and assuming you're driving relatively well you shouldn't move the wheel until you exit. Stock, you typically have to adjust the wheel a little while the suspension compresses. This makes predicting how quickly you can go through some corners difficult because they may have bumps in them that upset the suspension (and therefore the driver, heh).

      On the rear the issues are typical trailing arm/solid axle issues. It's very similar to the rear suspension under a NASCAR vehicle only we don't have power transmitting through it so that eliminates that issue (at least its not as bad as a stock Mustang rear suspension) Specifically the change in wheel base as the suspension moves up and down among others. Chrysler also adds a neat element where the rear locating bar moves the suspension laterally as the trailing arm moves up and down. Sort of a rear steer solution only it works when you compress enough of the stock soft rubber bushings and flexible rear arm to make a noticeable difference. Since it's also a solid axle setup the standard solid axle solutions apply quite nicely. Watts linkage, mumford links, etc. Specifically look at some of the solutions that the Lotus Super Seven clone builders are implementing.

      If you have your heart set on independent rear suspension, I'd look at a De Dion solution (modified solid axle setup, used on some Alfa Romeo's, etc.) that would probably be a little easier to implement since it shouldn't take up much more room than the stock rear axle solution. Next up would be to troll the local U-Pull-it type yards with a tape measure and find a suitable candidate. A completely removable sub frame would be easier to work with (Miatas and 2nd gen RX-7s come to mind) along with similar rear track and control arm length to the front suspension would help keep both ends working together. Though Bill Cultitta mentioned that the Stratus rear suspension would be a good solution since it's a little beefier than the Neon pieces and it should be 5x100.
      Stefan Mullikin's 2.2 - 2.5 equipped car upgrades

      If you feel like doing some manual labor, you can bolt in the turbocharged 2.2 or 2.5 liter motor found in the later K-based Chrysler cars.

      Find yourself a rusted out Daytona turbo car and pillage it for its stiffer suspension (larger swaybars, quicker ratio steering, and 4 wheel disc brakes) Grab the turbocharged drivetrain, wiring, fuel tank (buy a new pump and fuel lines though) and swap it all into place.

      Now the wiring will be tricky, but you should be able to find a later TBI-equipped K-car to grab the wiring harness from which can be combined with the Daytona harness, etc.

      To further the cheap and relatively easy suspension modifications, you can use the '90 and later cast aluminum control arms, K-member and uprights to greatly improve the suspension geometry of the car. If you really want to make a difference, build some spacers for the steering rack to decrease the bump steer (as the suspension moves, the steering angle will change slightly, kind of annoying) Buy a strut tower brace ( or modify a 240SX (Silvia) front bar to work on the K-car. This will increase the turn in response of the car immeasurably. The rear control arm from a later Daytona/Shadow/Lebaron performance model will have rear discs and a larger sway bar. John Spiva has Polyurethane suspension bushings for both the front and rear suspension (

      For wheels, whatever you can find will work. I think 16's are about the max I'd run on my cars but then I don't want to spend $2000 on wheels and tires for a $600 car. I've seen people running Daytonas with 17x8's and they look positively mean. So I bought some 15x7" American Racing Spyder rims off Ebay and shod them with 205/60 15 Yokohama's. When those wear out I'll probably put some 225/50 Kumho's on it. Luckily the bolt pattern of our cars matches with many other FWD cars. If you've got 4-lug wheels its 4x100, if you've got 5-lug wheels it 5x100. Heck if you want to use the larger 5x114 that the Mitsu use, you can swap to later model minivan hubs.

      Neons are a great source of wheels as they came with either 4 or 5 lug depending on the option package/year.

      As far as the engine goes: You can upgrade to the turbocharged drivetrain, just make sure you nab everything under the hood from the donor car as it's a system. Of course the modifications for the turbo motors are well documented on Gary Donovan's website as well as many other sites. Now, for the stock drivetrain, ditch the stock carb and emissions system. You can replace the carb with a Weber 32/36 DFEV (bolts on with some finagling of the throttle arm) You only need the one or two vacuum lines to run the car, the rest is just excess and my Rampage 2.2 passes emissions testing just fine this way. You can still find headers for the carbureted 2.2's which really help. Just make sure to use a long flex coupler and increase the pipe diameter of the system to at least 2-1/4" all the way back. IF you want to have some fun, pick up a side draft weber setup from Pierce Manifolds and freak some people out :) There was also a dual downdraft carb intake sold through Mopar Performance that used two stock carbs or two Weber 32/36 carbs. Also, Mopar Performance sold a supercharger kit for the early 2.2's which could raise the output to 150hp, which is about the same as a standard turbo motor with just much better throttle response.

      Mike Holler's mods and repair tips

      Chrysler 1904-2018

      Spread the word via <!--Tweet or--> Facebook!

      We make no guarantees regarding validity or accuracy of information, predictions, or advice - .
      Copyright © VerticalScope Inc. All rights reserved. Dodge, Jeep, Chrysler, Ram, and Mopar are trademarks of Fiat Chrysler Automobiles.

    1. · Premium Member
      3,295 Posts
      Performance Upgrades for the Chrysler, Dodge, and Plymouth 318, 273, and 360 engines

      by Keith Indy

      See Rick Ehrenberg's bolt-on performance tips

      The 318 is a good, solid and dependable engine. I will be the first to admit and try to sell that. Secondly, the 360 is an outrageously great engine because it has so much potential, greater than a Chevy 350 or Ford 302/5.0. The SBChevy guys have a little advantage because all the heads and intakes all bolt on without major changes other than combustion chamber and valve sizes. MOPARs have two sizes of runners and various valve sizes.

      What you have to do is make the determination of what you really want to do. A 318 can be built rather easily using stock components and be very reliable and strong, the 360 you can do the same thing with a lot more aftermarket options. About the only things that are different between the two other than the heads/intake, are motor mounts (right side, actually), harmonic balancer and torque converter (being external balance on the 360) and rear main being smaller on the 360 means oil pan will not interchange. The 318 does have the advantage of a steel crank stock, so power and rpm limitations are minimal.

      If you are on a 'budget', your best choice is to 'freshen' the 318 and only replace or machine items as necessary.

      There are some differences between the 318 and the 360, but many parts interchange. It is easier to get raised or decent compression pistons for a 360, not as easy for the 318. Another common thing is there is no replacement for displacement. 4 inch bore is always good as opposed to the 3.91 inch bore for the 318, but you can still get whatever valve you want into the head so that is not an issue either.

      There is no better source than either the MOPAR Engines or MOPAR Chassis 'Speed Secrets' books available through your nearest dealer.

      I always advocate that anyone who lacks experience and/or technical training and wishes to 'build-up' or 'modify' an engine, should talk to engine builders, ask lots of questions and read and learn. Read and talk to a reputable machine shop, talk to MOPAR people at car cruises and swap meets in your area and find out who they recommend in the way of a machine shop and go talk to them about a hi-po 318 build.

      First performance enhancement

      The first performance enhancement you do on a stock 318 is to install the (factory) 340/360 H.P. cam (or equivalent). With stock heads, 2Bbl carb and even 2.76 gears this is already a 'fun-package'. Even with 4.11 gears (and street tires), the FIRST 5 feet that the car travels is the most critical. Over carburetion or a non-functioning accelerator pump will pretty much have the same effect, the car may indeed 'fall on its face'. You will benefit from a quicker advance curve in the distributor and enough initial lead to give about 36 degrees max. A dist with 13 inside will double to 26 degrees on the crank then you can set the 'static' to 10.


      The 360 heads and Intake swap will fit on the 318, but the compression will be around 7.2:1, which is not very good for performance, which is not to say that the heads cannot be shaved .050 and intake be rematched to fit, adjustable rockers added to offset the rocker geometry, and away you go.

      The book says the 360 to 318 works well, but, take the 318 heads, shave .020 off the head, install 1.88 intakes vice 1.78, port the heads and you would have a better combination, especially on the bottom end response and will still rev as high as you want and float the valves before the power falls off (how can you beat that?). It can be done, but, if you have a 360, which is physically the same dimensions externally as the 318 and 273, why not go the least expensive route?

      Keep in mind that the 318 runs about 8.5:1 compression and will be about 8:1 or as low as 7.5:1 with the J heads of the 360. This is going to drop the compression pretty low, which is great for cheap gas, but bad for the performance side, thus most 318s are rated at the 185hp, which is a shame. If the engine is out and heads are off, do some measuring to determine what the compression is going to be. Some of the pistons can be as much as .080 below deck just to start with. I am not trying to squelch your combination, but, as many others have done with similar combinations, if it is a dog, don't be surprised.

      As stated, the piston sits between .025 and .080 down in the bore. The area of the chamber of a 318 stock head and a 360 J head is greater. Unless the block was 0 decked to the pistons, aftermarket pistons were limiting the distance below the deck, or the J heads are shaved, measure the compression or it will be lower than stock.

      Now, there is a solution to this problem. Last month's Hotrod mag had an excellent article similar to yours, but the heads were with smaller chambers. They shaved theirs .050 to raise the compression, whereas you may have to do the same. When removing that much metal from the heads, the cork gaskets front and rear of intake may be too thick, so be cautious during installation of the intake.

      Here is the thing about the 318 heads compared to the 360 heads. The intake valves are smaller on the 318, but the stock 360 valves put into a 318 head (1.88 vice 1.78) and then the bowl tuliped, vice opened up all the way, really makes the head flow in the chamber side. The pushrod pinch on the intake port is the same for the 318 and 360 head, so there is no gain there, but the height of the port is taller than the 318, and the port mismatch can have detrimental effects. Port matching can be done on most castings; some are close at the top of the gasket.

      Here is the hard thing to deal with on the 318 head of 1969: The exhaust valves will be sunk within a couple years because the seats are not hardened and need the leaded gas to survive. Figure you can get approximately 25,000 miles out of the heads before they are affected completely by sunk valves. Have the 360 heads shaved .020 or get new pistons is the best solution because the cost of the work on the 318 heads will be a couple hundred dollars and the porting time, if you do the porting yourself.

      Another solution is to hit the junkyards. I had several sets of 318 heads that were closed chamber that I have had in 73-74 Plymouth engines. Don't know the casting number but they do exist. Then put the 360 valves in the heads and port them. These heads already have the hardened exhaust seats.

      Intake valves are not affected. Did it on two sets of heads and have had wonderful results in the power increase world. I originally ordered stock 318 valves and ended up with stock 360 valves. Cut the seats, ported the heads, and really noticed the breathing and torque increase. It was fun!

      You can indeed 'shave' the (360) heads 20 or 30 to raise the CR but that should still keep it under 9.0 to 1 and allow the use of (cheaper) 87 octane. The power potential is already there, but everything has to work together; the timing, the intake and exhaust flow, the distributor curve, the plugs and wires, the cam specs, the carb itself, and even the type/grade of engine oil to make any 360 dependable, efficient and a pleasure to drive.

      The 340/360 intake is a larger runner than the 318/273 heads. This is like taking a 3/4 inch pipe and running it into a 1/2 inch pipe. They have to be port matched, or, if that cannot be done, find a 318 specific Streetmaster type dual plane intake.

      Smog is a concern for some of us, not for others, but there are some things that can be done without too much worry. For starters, we have to remember that the 34/360 have better breathing heads with larger ports AND larger combustion chambers. The amount of shaving to get them down to the 318 size, so as not to lose compression (takes it down to about 7:1 vice 8.5:1). An old favorite, and extremely helpful thing to do is have 1.88 valves from a stock 360 installed. There is a requirement to tulip the intake port to do this, but the small amount of work is well worth the effort and money. This also prevents having to change out the intake manifold to fit. If you do go with the stock 360 heads, you have to stick with a 360 intake, for the 340/360 heads and 318 intake do not match, and vice versa.

      Edelbrock makes a really nice aluminum head, with the smaller chamber size, if they are anything like the big block aluminum heads, would be fantastic, along with headers/dual exhaust and a 4 bbl and 600cfm carb (or police 4bbl), would add in the neighborhood of 100 hp/ftlb torque.

      Go out to the salvage yard and find a set of closed chamber heads. Anything past 1973 will have hardened exhaust seats for added durability. The closed chamber heads add compression and simplifies the need to shave so much off to raise compression. Get a set of 360 valves (1.88inch) and get the intake seats cut for them. Port the heads to gasket size and tulip the bowl to the valve size, but don't just bore the bowl out to the bigger valve. The less you shave the heads, the less likely you will need adjustable rockers. (big bucks to add).

      If you can't get a set of heads that are closed chamber, only shave the heads .020 so as not to throw the geometry for the rockers off any more than necessary. Get a set from the salvage yard and get them prepped and ready instead of waiting a week with your car down. Port match and bowl work is the best. Do not switch everything over to 340/360 heads and intake. It really kills your compression and stock ported heads run higher velocity for the 318, which you need.

      You suggested replace the stock 1.75 (or 1.78) /1.50 valves with the 1.88/1.60 360size. Other people recommend this as well. Now I know that the 318 heads are better that 360 for compression. My question is, would the 0.10' increase in valve area make that much difference on a slightly modified 318 (4bbl, duals, & quick bolt-ons)? Wouldn't it be easier & less expensive to increase the intake flow with a 252 (stk 360) or 260 (Crane) cam? Or 1.6 rockers?

      I-d imagine for competition you-d want larger valves, but for a daily driver, would the effort & machine shop fees be worthwhile? And what about increased fuel consumption? I-m thinking of installing late 80s #302 swirl port heads on a 318. (about 500cfm & duals, no headers) Has anyone done just this upgrade alone, that could verify performance gain & MPG difference?

      I did just this to my 74 Barracuda 318 when the wrong valves were sent to me and I was not in a position to wait for them to be replaced. The difference between 1.78 and 1.88 is 100 thousandths of an inch. That's one tenth of an inch.

      Mileage did not decrease, it actually increased because the added efficiency with the small runners breathed better, not worse. I was using the Crane .444 cam and it was superb. I could feel the difference from stock and it worked well. It was coupled to a Streetmaster dual plane and Hedman headers, ported heads, balanced stock rods and pistons, and Holley 650 double pumper, 2.71 rear 8 3/4 rear. Oh, exhaust valve change is not necessary.

      All the machine shop has to do is cut the valve seats, which I simply ground with the standard 45 degree stone cutter, then tuliped the cut to the edge of the seat diameter (i Marked the edge of the seat with the new valve, properly ground at 45 degrees, by doing a quick lap job on they dyed valve seat so I could tell how much material needed to be removed). Do not hog out the whole pocket because that just defeats the purpose of the tulip design. The charge enters the pocket, expands to the outward direction, as the valve is opened and then closed, the velocity in the runner remains packed and at a higher velocity, but the valve closing compacts a larger charge in the tulip area for higher charge to wait and enter for the next valve open motion. The idea of a higher lift cam will drop the vacuum and velocity of the charge and then you have no bottom end power.

      Going with the 360 heads, unless you are running high rpm and higher compression domed pistons, are pretty dead on the bottom end because of the size of the intake runners and drop of compression to low to mid 7:1. The bore is too small and the stroke is too short to get good bottom end draw on the 318.

      Magnum heads, although good, have poor pushrod geometry, so I don't like that idea too much. They work, but I fear bent pushrods because of the poor angles. 1.6 rockers, other than not being able to work stock on the early heads, and are around $450 with pushrods in the aftermarket. (extra cost). If you can go with a complete Magnum block to go with the heads, that would be the best thing.

      I could routinely wind this motor up to 7500 rpm without it dropping out, and one time slipped a gear on the highway to move quickly to avoid an accident and hit first doing 55(7500 rpm) and shifted at 75 before I really realized what had happened (panic mode to avoid the accident). I figure I hit 8400 rpm and not only did it not float or bend a valve, but was still picking up rpm and power before I could correct my mistake. A stock 1.78 definitely would not have been able to do that.

      It's your decision, just some good solid personal experience with this set-up. Need more info or help, just ask.

      Buy a set of 1.88, stock valves for a 360. I have personally found PAW to be an excellent mail order company. They have never steered me wrong and they have all the good stuff. You can find ads for them in all the car mags. At the machine shop, ask that the intake seats be ground to the size of the 1.88s, have the valves (new) redressed (just lightly ground to check them; little or no material is removed to verify factory tolerance and angle), and have the machine shop let you have the heads to do the seat position and port work yourself, then, when you have ported the heads as described, porting up to about 20 thousandths to the inner edge of the valve seat you have verified the valve will sit. Return the heads for assembly. If you have a friend, this goes a lot smoother, and can be accomplished in one day. Explain to the machinist what you want to do, and he will tell you how much it will cost. Valve grinds are usually around the $100-150 price range. Enlarging the seat may be slightly more.

      45-degree angle, by the way, is the stock angle for about 95 percent of factory heads. For the three angle valve grind, there is a 60 degree angle cut on the inside edge of the 45 degree seat that is about 30 thousandths inch, and then a 70 degree angle cut into the chamber. This isn't necessary if you are porting and especially with this tulip design porting.

      One reason I never like doing the 360 heads on the 318 is because the chambers are so large that you have to shave the heads .060 to get the compression up, have to use the 360 intake so there are not any vacuum leaks, and there is usually a flat spot on the bottom end because the intake runners are too large for the size of the engine. A good port job works good for the 318 heads, headers work well, and a dual plane intake with a 600 cfm Holley, or Carter, work well. Really want to make it a little better, get the closed chamber 318 heads, get a set of 360 intake valves 1.88 vice 1.78 (one tenth of an inch is a lot for a small engine, but they work really well), and port the intake runner in a tulip fashion from the floor to the valve edge. The small runners keep good throttle response, the tulip design packs the charge really good and adds a good amount of torque on the mid to upper rpm range. Cam selection is really good in the .444 range. Not too big to kill the bottom end, not so small that it won't rev to 7000rpm, either, and you won't need a stall converter with an automatic. There is a cam that was for the 340 in about this size, very nice. Remember, this is a small bore/short stroke engine, so they rev well, but too much lift and too large a runner (as in the 360 heads) does not work unless you are running above the 4000 rpm range, which is not feasible on the street, only the strip.

      Factory 360 heads are indeed larger inside than 273-318's. However, they are not nearly like Ford's (351) cleveland. Around 1978, MOPAR first sold the 'LA' version of the 318-4Bbl. They simply bolted on a 360 intake/thermo-quad. Shortly after, a (so-called) H.P. version was 'unleashed' on the motoring public. This version used the (current) 360 heads with the 1.88/1.60 valves. In fact, this H.P. 318 was available through 1984. Hey, some of you must have owned one.

      By 1977, 318 heads were only 1.0 c.c. smaller than the 360's. From 1968 through at least 1984, all 'LA' heads, either 318, 340 or 360 were of the 'open' chamber design. The 318 chambers were in the 61-62 c.c. range to 1975 then they slightly increased to about 63 and then to 65 a couple of years later. The 360 heads at that time were mostly 65's.

      If you mill either the 318 or 360 heads by about .005'', the chamber volume will be reduced by 1.0 c.c. Therefore, a cut of .050'' will reduce the 'c.v.' by 10 c.c.'s. This will in turn raise the C.R. by 3/4's of a point, on average; depending on the piston diameter.

      Finally, as taken right out of the MOPAR (factory) Engines manual, edited by Larry Shepard; "In general, the 318 lends itself to the 340 type conversion better than the 273, because of the larger bore, more cubic inches and basic low level of performance in standard 2-Bbl. trim. - - - the first conversion to be made will be assumed as the installation of the 340 heads (or 360). To install the 340 cylinder head (360 or '72-'73 340 is recommended on the 318) - - - The 318 bore does not have to be notched. - - - With the 340 heads installed, the next most likely change is the cam. - - - A good compromise choice for an automatic is the 'standard' 340 cam (1968-1971), - - - Now that the heads and cam installation have been discussed, the next step is the intake system. - - - etc., etc."

      Next find a set of late model 318 heads I believe the are 302 castings, circa 86-91 pre-magnum, they flow better than the early 360 heads and have swirl port heart shaped combustion chambers. Have the valve unshrouded, the ports mildly cleaned up and clean out the bowl area under the valves, for an intake use Edelbrocks dual plane intake set up very good for building power out of small cubes like the 318, buy there complete kit, intake carb, cam and lifters package which can be purchased thru Jegs or Summit for a small amount of money.

      Volunteer, one small correction to your open/closed chamber dates. I had a 74 Barracuda 318 with closed chamber heads in that car and floating piston pins, vice pressed pistons. I had to replace the motor after freezing and cracking a head (thanks mom and dad), and I found a 74 Road Runner engine of the same configuration. Might have been a fluke, but after about 1973, closed chamber heads have the hardened seats and closed chambers on occasion. Those really help to keep the compression with the rest of the smog pistons in around 8.5 - 9.0, depending. There is additionally, when you can find them, a tarantula 2 bbl intake manifold that is good for about 8-10 hp over the stock 2 bbl H pattern. I have seen them on cars, but usually on pickups and vans.

      I assumed that all '68 - '74 318 heads (with the '675' casting) were of the 'open chamber' design because that's what all the manuals say.

      When I rebuilt the original 318 from my brother's '70 Satellite back in '86, I remember that the chambers were 'round' and it did indeed have 'floating' pins, (like all 340's).

      I guess nothing is 'etched in stone'. My '74 Challenger should have a 'blacked-out' rear-end panel according to Paul Herd's resto guide but it definitely has a 'charcoal-gray bum' and I proved it. Thanks.

      P.S. I remember seeing the infamous 'single-plane' 2 Bbl. intake on a '71 Challenger and it had a Rochester carb., p.n. 7041180. Seriously.

      Hey Brad, I think the 318 heads would wheeze on a 360. I was debating myself on using my chiged' out 302' 318 heads cause I opened them up ALOT. But I'm thinking of staying with 360 heads instead. The intake runners are a lot bigger. Another reason why, is that I was told that going 2.02 intakes on the 302's was a bad idea, mainly because they would be too big for the 318. But looking at them more, (they are closed chamber) I think that putting in 2.02 valves would "shroud" and lose the effect anyway.

      318 heads have 1.78/1.50 valves,<--that might be 1.74 intake///

      most 360 heads have 1.88/1.60 valves, if you go with that, you can have the intakes enlarged to 2.02 and have the same thing as a 340 X head. Then just have it gasket matched and polished in the exhaust runners.

      Dana was mentioning 73? 74? 360 heads that were closed chamber as well, but I don't think he ever mentioned a casting #? If he did I've forgotten already.

      The closed chamber heads I was talking about were 318 heads. Boosting the compression by using 318 heads is one way to do it, and the smaller runners would work by opening them through porting. Thought on the subject is that the ports for a 360 can only be opened as wide as the pinch between the pushrods anyway, so gasket match and open up the runners wherever you can.

      Other solution, as shown in the 400hp 318 is to use the 302 heads. Shrouding of the valve is not an issue if you simply port the chamber as well. I noted from the pictures that they never took the time to round the closed combustion chamber so, there was probably another 15hp easy out of the combination. I just hate it when they do that.

      I do not know the casting number to the 318 closed chamber head. They were rather common early in the 318 history, but the 73-74 castings had hardened seats in them for unleaded gas, already.

      Note, I thought the 302 casting was the 318/360 pre-magnum design and was on both 5.2 and 5.9 before the magnum engine redesign? Did I misread the description?

      Also, dropping the 383 in the engine bay is quite a tight squeeze and a lot of work. I would not contemplate doing it without a full shop and lots of room, myself.

      Were you talking about rounding on the valve side, or also rounding the v at the top of the heart? I thought that was the "swirl" in the swirl port design?

      As far as I know, that's the same description on the 302's I've read, they still bolt up the same and all, the only real differences other then the chamber are the air holes, and the over sized 11/16 pushrod holes. Which is a bummer because i've had to be extra careful cutting in that area.

      I heard that they were also a template for some sb aftermarket heads, MP?

      After more thought, if any 318 heads were chopped and tricked they might be real monsters on a 360. you'd have close to similar sized runner to stock, but with all the obstructions gone, like a happy medium.

      I think Brad's thinking about regular open chambered 318 heads, it still would knock the compression up though, they just need to be chig'd out, which btw, i have an extra set just sitting around.

      That's about right. The 302 head with the small heart shaped chamber is fine to make the swirl, but after taking .050 off the top, it kind of destroys the purpose, thus, after the cut, the valves are shrouded, especially with the added valve size (which doesn't shroud the valve with the smaller valve). To make these heads work more efficiently, the edges of the machining process needs to be rounded, which will also allow more advance to be run, especially when they noted that they were getting the best results with less advance. SB always do best with about 38 degrees advance, brought in by 2400rpm, vacuum advance all in around 3500. They were talking about the best advance curve of a lot less, which confirms they had too much sharp edge, fuel not distributed properly. I would bet the piston top would show that there are quench areas at the spark plug top and the whole bottom of the piston. Poor flame travel because of the sharp edges.

      Just to set the records straight, there was only one 273/318 casting, #2843675, from 1968 through 1974. It was of the open chamber design, 61-63 cc's, and the valves were 1.78" and 1.50". In 1975 and '76, the #3769973 casting was used but there were no other significant changes.

      The next version was from '77-'84? but they were still of the open chamber config. After that came the 'infamous' and soon to be legendary - 302's.

      Volunteer, not to doubt you or the books, but I have had two sets of closed chambered 318 heads with the 1.78 intakes. Both engines they came off of had floating pistons (beside the point) and may have been Plymouth (one a stock 74 Barracuda, the other a stock 74 Road Runner). I do not know what the casting number is or was, but they are out there. I wish I had more information to help than that, considering they are not in your books.

      I rather liked the heads, simply punched to 1.88 intakes and ported because they would give the dropped deck flat top pistons a nice mellow 8.8:1 or so compression.


      Why new pushrods? Are you getting adjustable rockers (would be a good idea with anything above stock camshafts) to go with them? Stocks are pretty durable in other words, cupped pushrods needed with the adjustable rockers.


      Camshaft is the next best upgrade you can do for the 318.

      They really like the 340 hipo cam, which is still very mild, but is just enough to wake a 318 up. It has a lift in the .440 range, so any aftermarket camshaft between .430 and .455 work really well and mileage will not suffer, won't have to be high compression and doesn't require any high torque converter. Any more than that and you will kill the bottom end and the 318 will run like junk. This is an excellent cam for the 318.

      318s get a little radical with a cam larger than .450 lift on 270+ duration, 360s get radical when you get up to .485 and 290+ duration, so a .450 lift and 270 degree duration in a 360 screams, idles pretty smooth and will get a little better mileage without any sacrifices.


      Headers are a nice addition. If you don't want to go that route, split the exhaust and do dual exhaust, and that is another big help.


      As far as the ignition goes, stock MOPAR electronic ignition is one of the best factory designs out there, but an upgrade only gains with higher performance levels, not needed on the street, but it is your money.


      Notching a half inch deep slot from front to back in the intake plenum has a two-fold effect. It balances the idle signal side to side, which at low speeds/idle/cruising speed below 2000rps. If there is a slight difference between the two halves of the engine, it corrects this. On the top end, it helps a small amount by giving the assistance (very minor) as an open plenum manifold signal. It is kind of the best of two worlds without sacrificing much from either. This adds balance for the carb without sacrificing bottom end. Don't go larger than 650 cfm on the carb, as in Holley, and usually recommend 600 cfm vacuum secondary.

      (dana44 added:)

      Keith_Indy, a couple things to add about the three engines and a little info on the Magnum 302 heads. The 340 and the 318 share the same crank and rods, but there are beefier 340 rods around...the last couple years they were the same when the 340 started dropping compression and power. The bore for the 340 is larger than the 360 (4.040 and 4.00 respectively). The bearings are shared with the 318 and the 340, including oil pan and rear main dimension. Basically two rods available. All are stronger and heavier than small block Chevy and taking a belt sander and/or die grinder, not bench grinder, to remove the casting off the beams and balancing the rods is all that is necessary for anything you can build for the street.

      The 340 and 360 share intakes and heads, being the larger ports and low performance 340 had the 1.88 valves.

      There is, apparently, a misconception through an article between High Performance Mopar and the latest Mopar Muscle concerning the Magnum 302 casting and the Magnum block and heads. The Magnum heads with the swirl ports, closed chamber and rocker arms on bolt-on pivots, oiled through the pushrods, is different from the 5.2/5.9 Magnum engine and heads, and will work on the old 318/340/360 blocks with some minor mods. The lifters have to have an oil hole in them to push oil thru the pushrods to the rocker arms that match the heads. The 5.2/5.9 Magnum is a completely different animal, other than external dimensions and mounting points. The pinch area between the pushrods/ports is corrected by widening the lifter bore positioning and that is the geometry problem I was talking about concerning Magnum heads on an older engine. My mistake. On the other side of that, I still don't like to have to shave heads that much in order to raise compression because intake geometry gets tricky and not worth the real hassle of it, especially if it is done incorrectly. Deck height of the piston, if kept near zero or .010 is a better way to get the compression up. Maybe we can find a couple aftermarket pistons that can give us corrected deck height to list on here.

      One last thing for the 360, and that is the W2 heads. Stock they are better than anything from the competition, ported flow better than any big block engine, upwards of 310-320cfm. Thing is, they require a matching intake and rocker arm assembly, but if you have about $1600-1800 laying around, big numbers on the dyno.

      Good collection for reference. Thanks Keith_Indy for collecting it.
      Carburetor upgrade: by Daniel C. Stickney, 1996

      (Disclaimers and safety notice copyright © 1996 by Daniel C. Stickney)

      Proceed at your own risk. Some changes may shorten engine life or the integrity or durability of other components. The author makes no claim or guarantee that information contained in this article will be suitable for your situation. The author accepts no liability for any problems that you may encounter while working on your own car. Modifying your car may violate Federal, State and local emissions laws and regulations. Emissions equipment does make the world a better place (ask any Californian.) It isn't that much harder to set up an emissions legal system, especially with junkyard parts.

      All trademarks mentioned belong to their respective owners.

      Again, if the car is going be used on the street, check your local laws regarding tampering with emissions equipment.


      Be smart and work safely. Wear appropriate clothing and eye protection. Never, ever wear contact lenses in the shop. Don't assume that prescription glasses will provide adequate eye protection. (My glasses have ballistic quality polycarbonate lenses.) Wear goggles, a face shield, or glasses with side shields when using grinders or any tool that throws chips or sparks. Use gloves and eye protection when handling chemicals and wear ear protection if necessary. I shouldn't have to tell anyone about jackstands. If you work under a car without them you deserve to die. Think of it as evolution in action.

      Never start a project on Sunday if you need the vehicle to get to work on Monday. Always give yourself at least a full weekend in case you find that you need a special tool or part. Most accidents occur when rushing the job or working late at night to get done for tomorrow. Line up alternate transportation in advance (carpool, bus, or beater) and remember that you can't commute in a project. I plan on at least a week for any job that requires major disassembly. This gives me a cushion when I need to order parts. Finally, don't get frustrated! This is supposed to be fun! Try to work with a friend, preferably a knowledgeable friend. Listen to the radio. If you get stuck on something, STOP AND THINK! Get some coffee, talk it out with your friend, or your dog, look it up in the service manual. I find I can usually solve any problem if I get away from it and don't fight it.


      Beiseker Bob wrote that a 600-650 cfm carb is about right for a stock 318, and that a four barrel carb would add some fuel economy as well as power. He recommended a dual exhaust for some added pickup. With regard to cams, he wrote:

      if you want low-end torque and hi-revs is not really an issue, go with a hi-lift truck cam or something similar. What you'll be after is low duration, high lift. If you want to rev like a blender, go with lower lift, longer duration. The valves still open for a long enough period, but don't move as much, meaning less force on the springs, etc.. For a slightly hairy car, I've gone with a 0.450 lift (approx.) with a 290 degree duration. Does well in the quarter, but not so good for a street driver. If you're running an automatic be careful with how far you go, she may stall if you go too big.

      If you're running a stick you have a few more options. While you're surfing the net, check out the Crane Cams website...I think they have a 'cam selector' section to help you figure out what you need. They'll slide you a catalogue with all the good stuff listed and available packages.

      Another thing to look at is your gearing. I'm running higher torque, but with 2.90 gears. That way it'll still walk nicely, but cruise at 2100 RPM right smack in the powerband for that cam. Very important! If you're doing highway speeds and such, you don't want the engine to 'lug'. By the same token, if you're city driving, a rough idle will get on your nerves in no time...

      As for head work, a smooth finish on the intake ports and as mirror as possible on the exhaust ports. You want that fuel/air to spin on the way in, and get out after it's burned. If you can get some 'vortex' action happening in the intake, it'll work like making a whirlpool when you drain the dishwater out of your sink. When you create a vortex, or helix, you increase not only the velocity which slightly compresses the air, but also vacuum at the top of the vortex which sucks MORE air down with it. Think of it like a free turbo. Note that the intake ports curve into the cumbustion chamber and the exhaust just goes straight out. That's how you want to approach the porting. You want that exhaust gas to vacate ASAP after burning, so make sure it has NO resistance and not only will it exit faster, but the smooth walls will be less prone to trapping carbon particles and such. ...I'm thinking [this] would broaden the powerband all the way across, more poop per puff.

      ... Opening the ports would open your bottom end as well as lift the band a little higher. It would also raise the temp a little bit because of the extra burn. If you're just polishing, temp is not so much of a concern as you still have all that cast iron to help with the heat transfer. In any case, it wouldn't be a HUGE shift...for powerband, I'm thinkin' carb and bumpstick. Important to match these two so you've always got fuel where the cam turns on the most. Fuel specs for the carb should be available from the manufacturer.
      "Neil" responded: "My Dad and I did similar things to a '81 B250 Van quite a while ago. We started by taking the stock 2 barrel intake off and got an old Edelbrock Sp2P intake. They were smaller runner dual plane intakes designed during the late 70s and early 80s for mileage and torque. It flat works! We then increased the carb from the stock 2 barrel BBD to a Holley 600 vac Sec. (Stay away from the double pumper in the street). Put an Orange box 505 in for the Electronic ECU and a good dual exhaust with 2.5 in pipe and some Dynomax Super Turbos.That combo won't win races but the performance you'll get will be GREAT for torque and mileage.

      Richard Currit wrote about upgrading Diplomat 318s:

      Normally the computer for the lean burn system is mounted on the air cleaner housing. On a copcar it is located under the dash right above the drivers feet, so you can't see it under the hood. But you will have a dual pickup distributer. So check to see if this is what you have, if it does, yes it will be sluggish. First check to see if you timing is advancing with RPM's (mine wasn't on mine, the lean burn was shot, very sluggish) You can swap in a MP Electronic Ignition kit, very simple and only about $120 from Mancini Racing. The other thing to check is the oxygen sensor (does it run really rich?) its located in the exhaust manifold on the drivers side close to the spark plugs. If this is shot it will send a bad message to the computer and it will run very rich. My CopCar could barely get out of its own way when I bought it. MP Electronic Ignition, New Oxygen Sensor, and a rebuild kit in the carb (around $200 total) and it scoots pretty damn good. Will bark the tires nicely.

      (A.J. added: According to a friend who used to be a cop down in TX, the cop-version Diplomat/Fury didn't run too well-- that is, until they swapped-in an MSD ignition box. That simple switch, and it had all the power they needed.)
      Steve Knickerbocker wrote:

      Most people seem to think you need to scrounge for rare 340 A body manifolds in order to get some flow in the exhaust. Not so. My 72 Dart is running B body (79 Cordoba to be exact) exhaust manifolds on it's 360. Coincidentally, the 360 is out of the same 79 Cordoba. Yes it is close to the POWER steering gear box, but it doesn't touch or rub. I, too, thought I'd have to run some 318 manifolds to clear the steering but I had the B body manifolds and Y pipe on hand so I said, "I wonder?" They fit. I was a bit concerned about heat transference to the P/S gearbox so I added a P/S cooler and I have had no problems at all for the last three years. That is the only close spot.
      Steve also wrote:

      The 318 is a good motor and easy enough to hop up. In fact I was just reading Mopar Muscle's build up of a later 318, a 1985 in this case. They got 215 REAR WHEEL HP out of it with a cam and intake swap, still using the stock 1.75" intake and 1.50" exhaust valve no porting. The cam was a Comp Cams Extreme Energy grind, forget the exact one but want to say the 260 grind. The intake was an Edelbrock Performer, to save cash you can run a stock iron 4bb intake, and a Thermoquad.

      The next step was Edelbrock heads and a Performer RPM, which necessitated swapping on a 750 AFB. They got 273 REAR WHEEL HP then. That's like 340 crank HP.
      [email protected] (Opus) wrote:

      Find any Mopar from 73 to 75 with a 318 or 360 in a wrecking yard. Should be simple. Remove the distributor, ignition module, carburetor AND the ignition wiring harness. (it has a 4 prong connector) I am assuming you have a service manual so I'll dispense with details. Keep your old EPA approved parts. You may need them. If you choose to stick with a 2bbl (for economy reasons) then get an Edelbrock SP2P-2V-318 intake manifold. Yes it IS for 2 barrel carbs. Monstrous bottom end power but you sacrifice top end. Then replace the timing chain (a major weak point in 318's) with a double roller so you can advance the cam 4 degrees. This will increase your bottom end power. By this time you will have a sweet little engine that gets over 25 mpg and can easily bake your tires.
      Using a four-barrel on a 273 V8

      Bill Mertz wrote: "One source says all of the LA motors will interchange intake manifolds, the other source says, 64-65 V8s had a different angle on the intake manifold bolts, which are unique to those years."

      He was answered by Sandy Colter, who wrote: "You are right about the different bolt angle. You can most likely redrill or hog out the bolt holes as they are in the same place different angle. If [the replacement intake manifold] is a [Edelbrock] Torker or 2psp stay away from it. An LD340 or [Edelbrock] Performer are OK."

      Thomas Gottberg wrote: "The early 273 have different angle than the later, however as cylinder heads from 318 is easier to come by than the 4 bbl intake and the cyl heads are interchangeable through every year you may want to change the heads as well. In addition with the 318 heads you get bigger valves that would do your bigger carb justice. Obviously this will have some effect on the fuel consumption but I guess since you are considering a 4 bbl in the first place that has less priority."

      The following upgrades are copyright © 1996 by Daniel C. Stickney.

      Kickdown linkage

      Three years ago I installed a four barrel carburetor on my 1977 W150 Power Wagon and had a great deal of difficulty tracking down the parts for the transmission kickdown linkage. Many of these parts are obsolete or superseded. I couldn't find an easy source for information about these important but overlooked parts. So I put this list together to help others. However, my goal was to put together a working linkage, not an authentic one. I didn't pay any attention to whether or not these parts are appropriate for a restoration.

      Kickdown linkages come in two basic styles: The single-rod linkage and the three-rod linkage. Single-rod linkages tend to be model specific. The three-rod linkages are more generic. The easiest way to get the proper kickdown linkage is to find one in a junkyard. Unfortunately, many 1970's era Chrysler vehicles (i.e. Dodge trucks) are getting hard to find in junkyards (junkyards are full of Chevrolets for some reason) especially if you live in a rural area. You are also out of luck if your car did not come with a four-barrel option. So I put together a (not comprehensive) listing of the parts needed for the three link style kickdown linkage. (Parts are from 1983 Car manual unless otherwise noted.)

      top linkages

      • 4287 969 Throttle spring bracket
      • 4287 969 Throttle Cable Bracket with top bellcrank
      • 4041 548 Upper rod (carburetor. to top bellcrank)
      • 4027 590 Spring (upper rod to carburetor)
      • 4041 420 Middle rod from top bellcrank to bottom bellcrank (A727 transmission)
      • 4041 509 Middle rod. (A904 Transmission)
      • 3870 666 Linkage assist spring (middle rod to top bellcrank)
      • 3751 531 Stud for bottom bell crank
      • 3751 535 Bottom bellcrank (A727 transmission)
      • 3751 529 Bottom bellcrank, (A904 transmission)
      bottom linkages

      • 3769 198 Spring, bottom rod
      • 4027 374 Swivel, bottom rod (connects to trans. throttle lever)
      • 4173 225 Bottom rod for 318 with A727 trans. (will for other applications with a little blacksmithing
      • 4171 978 Bottom rod for 318 with A904 trans.
      • 3820 193 Bottom rod for pickup trucks, 360 w/ 727, (Obsolete)
      transmission levers

      • 3870 685 Transmission lever.
      • 2899 370 Transmission lever
      • 4095 310 Transmission lever (Pickup truck)
      parts needed

      • Manifold
      • Carburetor
      • Carburetor Gasket
      • Carburetor Adapter, (If necessary)
      • Manifold Gasket Set
      • Valve Cover Gaskets
      • EGR gaskets (If necessary)
      • Kickdown Linkage
      • Thermostat
      • Anti-freeze
      • Radiator Hoses (Top hose & thermostat bypass hose)
      • Vacuum Hoses.
      • Oil pressure switch
      • Temperature sensor
      • Fuel Hose
      • Fuel Filter
      • RTV silicone sealer
      • Spare hardware
      Notes and hints

      Get some service manuals, and read up before you start. I have always gotten factory service manuals for my vehicles. The factory manual has information that you can't find anywhere else. Aftermarket manuals vary in quality. Most of them are simply factory manuals condensed for the home mechanic. If you have to use aftermarket manuals, get several of them from different publishers as each may have something that the others missed. I once had an aftermarket manual that listed oil capacities in imperial pints!

      Use a torque wrench to install all torque-critical parts. Don't blame the gasket if you don't own a torque wrench. If you can't figure out how to use a torque wrench you shouldn't be working on a car anyway. You can rent torque wrenches but that may not be cost effective as good, hobbyist quality torque wrenches go for 70-80 bucks. Or you can borrow one from a friend. If you're a true car enthusiast I'm sure you have at least one friend who can loan you a torque wrench. Better yet, borrow the friend too. Manifolds can be heavy.

      Removing the hood will make the job go much easier. This is another place where your friends can help you. If they won't help you than they aren't true friends. If your car club friends can't help you, ask your best friend, i.e. your wife, girl/boy friend, significant other or main squeeze as hoods are no fun to handle alone. My wife helps me with mine.

      You have to remove the valve covers before you can remove the manifold. I recommend removing all parts from the top of the engine (Carburetor, coil, wiring harness, distributor) so you can get to the manifold bolts. You may need a socket and universal joint to get to the middle four bolts on the four-barrel manifold. You will need a universal joint if you are installing the relatively tall 1983-& later 318 "police car" manifold.

      Clean out the exhaust crossover/EGR passages on any used manifold before you install it (hot-tanking is best). Also remove the manifold baffle and clean out the oil & carbon deposits on the bottom of the exhaust passage. Good instructions for removing the sheet metal baffle covering the crossover passage can be found in How to Rebuild Small Block Mopar Engines by Don Taylor and Larry Hofer (HP books). While the used manifold is at the machine shop have them magnaflux it and check the gasket surfaces A massive vacuum leak is the wrong way to discover a cracked or warped manifold.

      While you have it apart, consider changing the oil pressure switch or adding an oil pressure gauge You can reach the oil pressure switch it easily once the manifold is off. A low oil pressure kill switch (Mopar Performance Part #P4120223) is also a good idea. This is also a good time to change the water temperature sensor, the thermostat, the choke mechanism, and the various pollution control sensors if you have them.

      Don't use manifold gaskets that block the exhaust crossover passage in a street motor. This causes severe driveability problems, especially in cold weather, and the choke won't work. These parts are for race engines only. Also, plan on replacing all of water and the vacuum hoses. It much easier to cut them off and replace them, and they usually aren't worth saving.

      Torque the manifold bolts carefully IN THE PROPER SEQUENCE and re-torque them with the engine hot. Mopar A engine intake manifolds are notorious for leaking near the exhaust crossover when improperly torqued. Use an anti-seizing lubricant on the intake bolts to ensure proper torque readings. Put the lubricant on the threads and the underside of the bolt head. Remember that you may need a universal joint to get the middle bolts, especially on taller manifolds.

      Never use Teflon tape on fuel connections. Tightening the fitting will tear off little bits of Teflon that can clog jets and other small carburetor passages. If a fitting leaks, replace it. Always install a new fuel filter. I like to use a high quality replaceable element filter. Remember that glass filters can break in an accident. Summit Racing offers some really neat carburetor inlet fittings with replaceable fuel filters built right into them for many carburetor models

      Make sure you have the right temperature range thermostat: Your engine will not run right without a thermostat. The temperature range you select will depend upon climate, intended use, and engine modifications. A 160 degree thermostat will not make up for a clogged radiator and a 195 degree thermostat will not fix a poor heater. Also make sure that you put the thermostat in the right way (point up, spring down!) A junkyard manifold may come with a different diameter thermostat neck then the one currently installed in your vehicle, make sure you use one for the right size hose.

      The single link style kickdown linkage is simpler and would probably be a better choice for a four-wheel drive vehicle. It doesn't need the vulnerable lower bellcrank and is unlikely to be jammed by ice or mud. However, these parts are obsolete and would only be available in a junkyard. Also, the single link style linkage is usually model specific. A linkage from a Cordoba may not fit a truck, etc. Make sure that the linkage you use does not interfere with the shifter.

      Note that there are several bottom rod/bellcrank transmission lever combinations for the three link style of linkage. These combinations depend upon the engine/transmission combination, the type of shifter and the vehicle. The wrong bottom rod may interfere with the shifter mechanism or mess up your shift points. You might have to experiment or blacksmith the rod a little, especially with junkyard parts.

      I used a stainless steel screw for the bottom rod swivel because I may need to adjust it someday. Also, don't use grease or oil on the kickdown linkage. The grease will collect road dirt and act as an abrasive. The linkage was intended to work without lubrication. Dry lubricants (like graphite) are all right.

      Finally, you may want to adjust the transmission shifting bands. This is easy to do if you have an inch-pound torque wrench , and eight point socket, and a factory service manual. One word of caution: After I got the tranny buttoned up I found the modulator spring in the drain pan, which meant that I had to take it apart again! This was not happy news at 10:00 on a Sunday night. (see shop safety, above)

      Carburetor choices

      There are too many carburetor choices available to discuss more than general principles here. A general statement for carburetors is don't over carburet! An oversized carburetor will produce economy and driveability problems. At worst, an oversize carburetor will provide more gas than your engine can burn, causing oil dilution and spun bearings. A massive tunnel ram may look trick, but it is hard to look cool when you car bogs at the starting line or stalls at the light.

      Gary Lee wrote: Installing a carb that is too big for a given application does not bog the motor down with too much fuel. The problem is too little fuel and too much air.
      Spread-bore carburetors and carburetors with vacuum secondaries, air valves or air doors are more tunable and forgiving. Later model spread bores like the Carter Thermoquad and the Rochester Quadrajet are "one size fits all" carburetors designed to work on a range of engines with jet changes. They can get away with this because vacuum secondaries and air doors won't give the motor more air than it needs.

      Vacuum secondary carburetors provide better gas mileage, and may eliminate bogging while providing better pickup in heavy vehicles. Mixture rod carburetors are easier to fine tune than power valve carburetors because you can replace rods without disassembling the carburetor. (You still have to disassemble the carb to change jets, though.)

      Which setup you choose depends upon what you do with your vehicle. I use my 1977 W150 Power Wagon as a farm truck and I pull a 12,000 lb horse trailer, so my main requirements are low rpm power, driveability and reliability. My truck usually stays parked all week and works hard on weekends. It has to start and idle in cold weather and it has to start and run for my non gearhead wife without goofy tricks or voodoo.. It can't be too loud. It has a stock 360 w/ headers and a cold air induction system. I don't have much money to spend on it. My setup:

      • -1983-86 318 Police Car intake manifold. (junkyard)
      • -Carter AFB 9626 625 CFM carburetor w/ adapter
      • -High volume fuel pump
      • -Air cleaner from 1975 Cordoba 4-barrel with hot air valve. (junkyard)
      • -Radiator support cold air intake from 1979 Little Red Express.
      • -Replaceable element fuel filter
      • -Mopar high performance (orange) ignition box with recurved distributor
      • -Headers with carburetor heat stove.

      Everything has tradeoffs. The simple square bore carburetor trades a little fuel economy, driveability, and top end power for low end power and reliability. Likewise, the iron manifold trades power for cold weather driveability. The Cordoba air cleaner is more restrictive than an open element air cleaner but it is quieter, improves driveability and emissions, and allows me to use a leaner mixture. Finally, the whole setup was cheap. This setup produces about 10 to 11 MPG in mixed driving, which is better than the two barrel 318 that it replaced.

      Scott Preston wrote:

      Here is the math to figure out the size of carb you need. Max rpms you will turn with the engine times its cubic inches (is it a stock bore or oversized, exact number is needed), divided by 3456, times 0.85 for street carb. So for example if you're working with a 273 and its max revs are 6,000 rpm:

      273 x 6000rpm=1638000/3456=474 cfm x0.85=403cfm carb

      If you get a 450 cfm carb you will be oOK.
      Engine tuning

      Once you have your system installed and running you need to tune it for best performance. The best thing to do is take the vehicle to a facility that has a chassis dynamometer. The next best thing is a an oscilloscope. I dialed in my truck the old fashioned way by keeping a log of appropriate parameters (Idle vacuum in neutral and drive, jet & mixture rod size, mixture screw settings, accelerator pump setting,) Under this I would write down the driveability and MPG that I observed. I also made up a matrix that cross tabulated jet and mixture rod sizes so I always knew how to achieve a relatively leaner or richer mixture.


      Anthony Matlock wrote:

      I had no need to alter or replace my kickdown on my upgrade to a 4bbl Holley. The only major modification to my linkage was with the throttle cable. I purchased a CSI Racing throttle bracket, which according to the manufacturer would not work for my purpose. I ground down the protrusions on the cable that prevented the cable from going through the mount. I used a couple of nuts and screws to provide as the mounting points for the cable and the kickdown. The kickdown is fully adjustable now that I have a nut and bolt placed in the slot to provide as a stop. I would advise that you would only need to replace the valve cover gaskets if they are old, leaking, or the new manifold is equipped with an EGR valve, otherwise the replacement is not needed. I must note that the intake is an Edelbrock Performer series aluminum manifold which is taller than any of the stock intakes available. This posed different challenges which I had to deal with.
      Swapping a 360 for a 318

      KOG wrote about replacing a 318 with a 360, in a 1970 A-body: "You need a left motor mount bracket for 360, balanced torque converter, 3 piece kickdown rod (A body - which you should have) and driveshaft front yoke. Driveshaft will have to be shortened and the 7-1/4" rear axle will have to go - which it will do shortly without any additional help. An 8-1/4" from a '74-'76 V8 will work (2.45 gear) or you can try to hunt one of the fairly rare 8-3/4" axles from a 340 car. You'll really want to get the K member and disc brakes from a '73-76 while you're at it - the 360 is MUCH quicker than the 318." ... " you'll have to change exhaust Y pipe or use 318 manifolds - which will choke the 360 somewhat. The 904 and the rear axle will not tolerate much full throttle use of a 360. The brakes on the car are flat out inadequate for the 318, never mind the 360."

      Engine links


      • Hot Rod's Chrysler Engine Swapping Tips and Techniques for $13.56 (20% off). This is still one of our most popular books!
      • Chrysler Performance Upgrades, by Frank Adkins, with wiring diagrams and charts. $15. Covers performance cars of the 1960s and 70s. Written by a master technician, covering engine swaps, suspension upgrades, transmission mods, brake improvements, rear-end interchanges, and more.
      • The Haynes Chrysler Engine Overhaul Manual, $13.60 (20% off). Another very popular book.
      • How to Make Your Car Handle by Fred Pohn. Covers a number of techniques
      • Ultimate Guide to American V-8 Engines : 1949-1974 ~ $15.96 - Detailed specifications and descriptions for all U.S. V-8 engines between 1949 and 1974. Roughly equal coverage for most engine families, though lower-performance engines seem to get less text. Photos are excellent. There is a ton of information in this book, on each American V-8 engine. It includes identification notes and many details and tables. There could be more photos. Based on the number of people who helped, we suspect it's the last word. In short: we recommend this book, and think it's bargain priced.

      Chrysler 1904-2018

      Spread the word via <!--Tweet or--> Facebook!

      We make no guarantees regarding validity or accuracy of information, predictions, or advice - .
      Copyright © VerticalScope Inc. All rights reserved. Dodge, Jeep, Chrysler, Ram, and Mopar are trademarks of Fiat Chrysler Automobiles.

1 - 4 of 4 Posts

Forum Reviews

Be the first to review this product

Write a Review

Do you have experience with this item? Help our community members and share your knowledge.

Sign in to add review