1970-1994 Plymouth Duster and Dodge Demon cars

340 duster

Four years after the first Valiant, Plymouth unveiled a sporty fastback version, the Barracuda. Critics praised its handling, but people wanted big block engines; so the Barracuda moved to a big new body, leaving a hole in the “light-and-sporty” class. Plymouth wanted to fill the hole, but the company had no budget for it, just $15 million earmarked for rearranging the Valiant’s sheet metal.

1970 plymouth duster

Gene Weiss, the Plymouth compact car product planner, worked with Plymouth stylists (notably Neil Walling and Milt Antonick) to create a new car on the budget of a styling refresh. The 340 V8 powertrain, from Dodge’s parts bin, would give big-muscle performance, but since Swinger sales weren’t that high, they knew more was needed.

How could they make a sporty compact on the budget meant for a quick facelift? They would have to keep as much as possible from the four-door Valiant, including the entire nose, both bumpers, most of the suspension, and the floor pan — which meant keeping the Valiant wheelbase and length.

duster 340

Gene Weiss tapped Milt Antonick, supervisor in the compact exterior design studio, and an expert at making something of value out of what was available (as they dubbed it, “junk yard styling”). Milt, in turn, called upon Neil Walling, a junior stylist who had been working on the full sized Plymouth, to make some sketches.

Neil Walling dropped everything else, and within days had the sloped rear, wide rear fenders, and metal crease lines that fit perfectly with the Valiant. The design called for sharply curved side glass, moving from the industry’s 90-inch maximum radius to a mere 45 inches, which would have to fit into the existing Valiant door.

1970 plymouth duster

While PPG worked on actually making the glass, Advanced Car Engineering’s John Worthy was brought in to stuff new windows into doors not designed for them. Worthy made the sharply curved glass work inside those doors, in a couple of days — without this, the car would never have been. The curve dramatically increased the round look above the belt line, sweeping away the “made from Valiant parts look.”

The Duster’s taller trunk lid meant three cubic feet of extra storage space. The rear window was flush-mounted to cut air drag, which may have made a large difference in noise, responsiveness, and gas mileage at higher speeds versus the Valiant’s concave window. On the down-side, because the Valiant sedan’s rear axle was kept to keep costs low, the rear track was two inches too narrow on either side, compared with the sketches.

1976 Figures WheelbaseLengthWidthHeightHeadroomLegroomTrunk
(cu. ft.)
Valiant Sedan111199.6715438.3 / 37.341.9 / 35.216.6
Plymouth Duster 10819771.753.4 37.2 / 36.4 41.9 / 29.420.1
1994 Duster97.2171.767.352.738.3 / 41.441.4 / 3413.1

Other flaws cropped up later; for example, the tail lights, which had no bezels, attracted rust, while the rear panel caused a high lift-over to the trunk. The flat deck lids had no handles for closing, and slamming them by the lip resulted in creases or small dents. Plymouth rushed a redesigned lid into production, with a strengthening vertical rail down the center, early in the 1971 model year.

Plymouth Duster dashboard

These were relatively minor complaints on a phenomenally successful car — one that leveraged and built on the Valiant’s many real strengths, but with a much sportier look, a substantially larger trunk, and less wind resistance.

From sketch to final design, creating the Duster had reportedly taken all of six weeks! 

Enter the Plymouth Duster

The Duster concept name came out of an advertising agency suggestion; it had performance and a bit of humor in it, because when you were outraced, you had been “dusted.”

The 1968 Plymouth Road Runner had proven that characters could sell, so the company approached Warner Brothers with the idea of using the Tasmanian Devil. Warner Brothers turned them down or asked too high a price, so designers created their own character, a swirl similar to the Tasmanian Devil in flight.

340 engine

Meanwhile, Milt Antonick was considering the 340 ci V-8, one of the best performance V8s ever built by Chrysler; rated at 275 horsepower, some say it had an easy 320. With the 340, the Duster could easily beat the Nova 350 and its Ford equivalent, and even go after some of the big-block cars.

plymouth duster car photosMilt Antonick drew up a small image of a telephone booth, with the letters “C K” beneath it — standing for Clark Kent (Superman). He also put a 36-square-inch Superman-style “S” on the engine silencer pad, having secured the rights from DC Comics.

Chrysler-Plymouth Assistant General Manager R. K. Brown reportedly thought it was a ridiculous concept; he could not grasp what a telephone booth had to do with marketing a car. That was the end of the Duster CK, which became, simply, the Duster 340.

The 1970 model was first titled as a Plymouth Valiant Duster to build off the strong reputation of the Valiant. This would change for 1971, when the Valiant name was dropped — just as the original Valiant Barracuda quickly became the Barracuda.

valiant duster diagram of the cars

The Duster was based on solid and proven Chrysler engineering: unibody construction, front torsion bar suspension, Torqueflite automatic, and, for the Duster 340, full instrumentation with an optional tachometer. The 340 V-8-powered Duster became a member of the Plymouth Rapid Transit System. It could reach 130 miles an hour, and pulled a 14.5 second quarter mile at 99 miles an hour — within the range of the 440 V-8-powered B-bodies.

How did people react to the Plymouth Duster?

The Plymouth Valiant Duster went on sale on September 23, 1969.

Car Life rated the Duster 340 with a TorqueFlite automatic in March, 1970. They obtained 0-100 mph in 17.5 seconds, with a quarter mile time of 14.7 seconds @ 94 mph. Gas mileage was 14.8, good for the performance. Weight was 3,520 pounds as tested, and it cost just $2,547.

The Duster tended to understeer, but even at triple digit speeds, it was as competent as any reasonably priced car on the road.

car sales

At the end of the model year, Plymouth had sold an incredible 217,192 Dusters, easily beating the Barracuda’s run. When the Duster and four door sedans were added up, Valiant easily broke its previous sales record with 268,002 cars sold. A car that had been sliding downhill was now moving up.

Starting at $2,172, not much more than the 1960 Valiant, the Duster represented a fantastic car for the money, even if you had to pay a bit more for front disc brakes, power assistance, or both (the sweet spot was non-assisted front discs). Compared with the Ford Maverick, the Duster had 4.5 more cubic feet in the trunk, 11 inches more hip room in the rear seat, 3.5 inches more in the front, bigger brakes, more options, and a far better warranty.

Plymouth Duster

For 1971, the Duster 340 got a huge Carter Thermo-Quad carburetor, new front-end styling, twelve new colors, and a new side tape treatment. Keeping up interest with little money, Plymouth developed another package, the Duster Twister [see the end of this page] that had the looks of the Duster 340, without the thirsty engine.

With sales through the roof, Plymouth stylists went back to work, developing the next generation. John Samsen, who provided the following photo of a full sized clay model, wrote in 2010, “I think it is a proposal for an all-new Duster for 1973. I don’t know if it was to share Valiant sheet metal, or be on its own. Anyway, it was never put into production. Note how similar it is to present-day compacts! Except for the door handle, it could pass for a contemporary car design.”

1970 Duster clay model

The Dodge Demon joins the Dodge Dart Swinger

1971 Demon 340

Dodge dealers demanded a version of the hot-selling Plymouth Duster, and, as always, they got what they wanted — the Dodge Demon. The company, to be fair, gave Plymouth a version of the relatively slow-selling Dodge Swinger in return.

dodge ad

Product planner Burton Bouwkamp said, “The Dodge Demon was named by the Dodge sales department because they envisioned an ad that said ‘Come in for a Demon-stration.’ The Demon name didn’t last because some religious groups formally objected to the Demon name.”

1971 dodge demon

The Dart Demon Sizzler was “strictly for the young. No way is your Aunt Martha going to understand the way it looks. Those tripes, Rallye wheels, and other ways of turning her off and you on.... If you’re young enough to understand it, you’re young enough to buy it.” It was essentially the Duster Twister: the hot Demon looks, with a slant six (optional V8). It had racing mirrors, 14 inch whitewalls, stripes, “Tuff” steering wheel, plaid bench seats, carpet, flat-black hood treatment, stripes, Rallye wheels, Sizzler decal, and a body-colored grille if the body was painted Hemi Orange, Plum Crazy, or Citron Yellow.

sizzler

Demon sales only hit 40% of Duster sales; but the Plymouth version of the Swinger, dubbed the Scamp, turned 48,253 people into Plymouth owners, 48% of the sales of the Dodge Swinger. After 1972, the Dodge Demon was renamed to Dodge Dart Sport.

demon and swinger

Road Test looked at the 340 Dodge Demon automatic in April 1971. They got 0-60 in 7.8 seconds and a 14.6 second quarter mile at 96 mph. Estimated top speed was 127 mpg, fuel economy about 15-16 mpg. They rated the cornering, finish, luggage space, performance, and steering to be excellent.

1971 Dodge Demon

Changes: 1972-73

Owners of the Duster and Demon had some advantages over owners of Swingers and Scamps; the rear of the Duster was designed for aerodynamics, and greatly reduced noise and increased highway gas mileage. Cruising became easier. The high deck lid also dramatically increased trunk space, giving coupe owners far more storage than sedan owners, even if it made it harder to get things into the trunk.

1970 Duster

Back in 1970, the company had planned an all-out makeover for the 1973 model year. The stylists prepared for softer, rounder Darts, Demons, Dusters and Valiants. The company hit hard times, and the new styling was cut; still, the cars kept on selling, just as they were. They owned 30% of the compact-car market, huge for Chrysler.

gold duster

After selling 100,000 units, Plymouth turned out a Gold Duster option package. It was a dressed up version, designed to turn “prospects” into “prospectors;” it included the larger slant six or a 318 V8, with added trim, dual horns, and a cigar lighter.

Changes to the cars for 1973; the Space Duster

Portions written by Lanny Knutson. Copyrighted by the Plymouth Bulletin. Reprinted by permission.

The Valiant and Duster were both given a more “formal” look for 1973, their last major styling change.

A more aggressive hood rose above a three-segment grille, flanked by squared headlight bezels. The massive bumper would later gain large rubber guards to meet new crash standards; it still looked more natural than some other solutions. Large single-unit taillamps flowed with the Duster’s rear sheet metal, while other Valiants remained unchanged in back.

1973 Plymouth Duster 340

Chrysler’s famed Electronic Ignition System, phased in during 1971, was installed on all engines late in the 1972 model year. With no points or condenser, it boosted voltage by up to 35% for better cold weather starting and fewer misfires. Emissions goals were met with exhaust gas recirculation, a troublesome orifice spark advance, and a resistor which shut off the choke more quickly by heating its “sensor” (spring).

duster twister

power disc brakes for 1973 plymouth carsDisc brakes were standard on all V8s, optional on the sixes, with power assist standard in the Duster 340. Inside, shoulder belts were stored above the doors; they were awkward at best until 1974, when they became single-piece, flexible designs.

The Twister and Gold Duster returned, augmented by new Space Duster and the Special Coupe packages. The Space Duster revived the old Barracuda folding rear seat, with a carpeted trunk that could extend to 6.5 feet and an optional sliding sun roof. The Special Coupe had pleated vinyl seats, a full vinyl roof, and vinyl-insert side trim to make a more upscale look; it also included the Spacemaker Pak from the Space Duster.

The standard six was the 198, now at 95 horsepower, replacing the 170.

Insurance companies were charging outsized rates for high performance cars; the Duster 340 had 15,731 sales this year, the most it would ever achieve. Insurers hadn’t gotten around to figuring out just how fast the 340 truly was. The 1973 oil crisis helped to knock off high performance V-8 engines as well: it wasn’t the price per gallon, it was whether you could get it at all, and how long you had to wait.

The gas crisis boosted sales of all the other Valiants, Dusters, and Darts; Valiant production for the calendar year rose to 402,805, including around 265,000 Dusters, helping Chrysler to increase sales by 13% and nab a 15.6% market share.

1974: Valiant Scamp becomes the Brougham; luxury pushes out sport

1974 was another banner year for the Duster, though there were no styling changes. Under the hood, the 360 cubic inch V-8 replaced the 340; originally created as a smog motor, it was a good performer, with 245 horsepower. Only 3,979 Duster 360s were sold, as gas prices, gas lines, and insurance rates hit.

1973 duster

Styling had gussied up the Valiant Scamp, turning it into the Brougham; and people went nuts for it, snapping up 127,430 copies. The Brougham’s luxury appearance included plush velour, targeted to people who owned more expensive cars, but now wanted better gas mileage. The Brougham pushed Plymouth into an easy third place in production; total assemblies amounted to 476,818 cars!

Dusters became safer and easier to drive with shoulder belts that would “give” when drivers leaned forward, and could be attached in one movement. The government also insisted on a seat belt lockout, so that the engine could not be started when the driver (and passenger, if one was present) did not have their belts on. This 1974-only “feature” could easily be eliminated in the Duster (and Dart and Valiant) by disconnecting the wires underneath the seat.

The Dodge Challenger and Plymouth Barracuda ended production in April 1974. The original, light-weight Barracuda had been the correct answer after all.

The last Plymouth Valiant Dusters: 1975 and 1976

The Valiant Brougham was a big hit, and Plymouth followed it up with the Duster Custom. The full-length rocker and taillight panels that decorated the Custom were optional on other Dusters.

Plymouth Valiant Duster - cars of 1975

The grille was changed for 1975, with a more finely-meshed plastic that had silver coating in front and black behind; the effect was more upscale than the 1973-74 grille. White parking light lenses hid amber bulbs (in 1976, those colors were reversed). Seat belts were improved again, and were less balky than the 1974 units.

towing

The Gold Duster and Space Duster Pak continued; radial tires, a fuel-pacer system, and a tighter torque converter helped increase fuel economy.

Word got out early about the planned replacement for the Duster and Valiant. Chrysler was working on an enhanced Brougham idea, with profitable upscale compacts. Its early publicity gave people a reason to not buy, and sales dropped. The Brougham was still popular, as Fury and Monaco owners swapped out to the smaller cars.

Only 1,421 360-powered Dusters were sold in 1975, and they stopped being an option in 1976.

There were just 8,455 Scamp sales in its final year; the Duster, in its last year as an A-body, eked out just 26,688 sales — despite the addition of the lightweight, high-mileage Feather Duster and the less inspired Silver Duster.

1976 Silver Duster

The Silver Duster was basically a trim scheme and package, like the Gold Duster.

silver duster

The Feather Duster was another story entirely, with aluminum for the trunk bracing, inner hood, bumper brackets, and intake manifold; that cut weight by 180 lb — around 5%. It had a smaller carburetor, special distributor calibration, larger exhaust, and a 2.8:1 rear axle ratio, with the usual automatic or a four-speed overdrive manual transmission.

The Feather Duster was slower, but it gained an EPA mileage rating of 22 city, 31 highway with the automatic — a stunning 24 city, 36 highway with the manual. The Duster was larger inside than most other economy cars, and was a fine alternative to the even slower and more rust-prone Japanese imports of the time.

All the Dusters, and all the Valiants, had one styling switch for 1976: the white lenses covering amber parking lamps were changed to amber lenses covering white lamps, making the grille somewhat more attractive.

1976 Plymouth Duster cars

In its August 1976 Car and Driver, William Jeanes reported on a one-off show car built by Plymouth and called the “Fonzmobile.” Based on a Duster 360 and capitalizing on the TV show “Happy Days,” it had a flame paint job, exhaust under the body sill, dummy dual spotlights, wide whitewall tires, baby Moon hubcaps, a fold-down rear seat, and a sliding sunroof. The idea was to entice owners of the 1,173,000 used Dusters and Darts on the market to modify their own cars.  (This paragraph was from Jim Benjaminson writing in the Plymouth Bulletin, reprinted by permission.)

sunroof

Finally, the Duster quietly slipped away. Most analysts felt that Chrysler could have kept right on marketing the Duster for years without major alterations; a stunning 1,328,377 Dusters had been assembled in just seven years.

Now, though, the press was in love with the Plymouth Volare and Dodge Aspen. Motor Trend Magazine named them the “Car Of The Year” for 1976, and Consumer Reports approved as well. With all the uproar, it was easy to forget that the Duster was still around for 1976.

Plymouth Twister

Dave Duricy wrote that the Plymouth Duster Twister option package cost $100 and included a large variety of trim and stripes, but no engine enhancements - a sheep in wolf’s clothing. It started in mid-1971, with Rallye wheels, racing mirrors, side and lower deck stripes, a flat black hood, Swinger 340 hood scoops, and a unique 340 grill; but the biggest motor was the 318 V8. For 1972 the Twister lost the special hood but gained a cartoon “twister” near the tail-lights.

For 1973, according to Jesse Moser, the hood stripe followed the top edge of the hood, and the late-1960s Formula S type scoops were used; the cartoon disappeared, and bucket seats became an option. The Rallye wheels should be free of trim rings and a front anti-sway bar should be underneath, through to the last Twisters in 1974.

Steve Brown quoted Galen Govier as saying that the 1972 Twister Package was officially the A51 Accessory Group. The drip rail and wheel lip moldings and the Twister decal were only available as part of the Twister Package.

Plymouth Volare Duster

Plymouth Volare Duster

The Volare coupe looked much like the original Duster, even down to the optional fold-down rear seat, but it didn’t have the same name; it was a Volare Coupe, some sold with the Road Runner package. The Volare and Aspen coupes had shorter wheelbases than the sedans, to avoid wasted space between the seat-back and rear axle (according to Lanny Knutson in the Plymouth Bulletin).

Volare RoadRunner

The hottest engine for 1976 was a two-barrel 360 with just 180 net horsepower, capable of (according to Motor Trend) 0-to-60 mph in 8.6 seconds.

The Duster name finally returned in 1979, as an option package on the Volare coupe — designated as RPO A42, according to Walter Ronk — which cost $30 ($90 more for the Duster décor package). 1979 Volare production, in total, was under 135,000. Bringing the name back hadn’t helped; in 1980, Duster Package production was just 5,568, while Road Runners dwindled down to a mere 496. Either the time or the car wasn’t right, but they would try again.

Horizon-based Plymouth Turismo Duster

The Plymouth Horizon, based on a Simca, was a hot seller; it had light weight and an independent front suspension. The Turismo and Charger (TC3 and O24) swapped out the economy-hatchback shape for a sportier, low-slung form. Now, the Duster was merely a trim level, with nary a single stamping changed from the Plymouth Turismo. (Why not just use the Duster name instead of inventing Turismo? We don’t know.)

Turismo and Plymouth Scamp

The Plymouth Duster package was launched in 1985, adding a rear spoiler, rallye wheels, and stripes to the Turismo. For 1986, the lineup went Turismo, Duster, and Turismo 2.2. The Duster added special bucket seats, wheels, and trim, but the Turismo 2.2 had a much higher-performance engine. There didn’t seem to be much of a point now, but that would change, a bit.

Plymouth Sundance Duster

The Plymouth Sundance had a sporty two-door RS, with a turbocharged 2.2 liter engine, until 1992. At that point, Plymouth switched to a Mitsubishi 3-liter V6 that was less powerful than the turbocharged four — and made it standard on the new Sundance Duster.

plymouth sundance

The Plymouth Sundance Duster was, again, just a trim level, replacing the old RS; it included the V6 and more standard features, with the stiffer suspension that went with the top engine, but you could drop the V6 and get the Duster with a 2.5 four-cylinder.

woodgrain dashboard

For 1993, Duster had seat and door trim fabric upgrades and realistic-looking faux-wood bezels.

The last year for the Plymouth Duster was 1994. It was replaced by the Dodge and Plymouth Neon; finally, the Dodge Neon SRT4 took the place of the Duster 340.

valiant.org 1966 Duster Sportwagon drawings
340 V8318 V8Slant Six

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