1970-1994 Plymouth Duster and Dodge Demon cars

340 duster

After the new “Valiant by Chrysler” was launched for 1960, Plymouth created a sporty fastback version called the Barracuda. When the horsepower wars gained traction, Chrysler created a new body for the Barracuda that could take big-block engines; but that left room in the “light-and-sporty” class. The company was prepared, with another inexpensive take on the Valiant.

The Plymouth Valiant was economical and dependable, but with its thin margins, Chrysler did not have much money to invest in it. Still, $30 million was set aside for a 1970 makeover, to be shared between the Plymouth Valiant and its long-wheelbase twin, the Dodge Dart.

duster 340

Just dropping in a 340 V-8, though it solved the performance gap, didn’t boost sales; the existing Dodge Dart Swinger 340 wasn’t flying off the shelves. Plymouth had just $15 million to solve the problem, and that was just enough cash to rearrange the sheet metal on a low-margin car.

sunroofBecause of that budget, the designers carried over whatever they could from the four-door Valiant: front sheet metal, floor pan, all bumpers, quarter panel inserts, drivetrain, most of the suspension. Designers could then come up a neat looking two door — with the as long as it had the Valiant wheelbase and length.

It had to be done quickly. Getting tooling machines on line for production takes a long lead time, so the body had to be in place just as soon as the styling folks got it together. The rear axle track wasn’t changed, due to cost, and it remained around 2 inches too narrow on either side to coincide with the sketches.

The Duster had a smaller rear seat area than the Valiant, but three cubic feet of extra storage space. The rear window was more aerodynamic, and flush mounted to lower drag.

Gene Weiss, the Plymouth compact car product planner, conspired with Plymouth stylists (notably Neil Walling and Milt Antonick) to bet $15 million on a long-shot car allegedly not approved by higher management. The 340 V8 would give it big-muscle performance, like Dodge’s Swinger 340; that also provided the components they needed, from the parts bin.

Plymouth Duster dashboard

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 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 his starting point, with the sloped rear, wide rear fenders, and metal crease lines that fit perfectly with the Valiant. The design called for sharply curved side glass; Walling wanted to go from the industry’s current 90-inch maximum radius to a mere 45 inches, which would have to be made, installed, and fit into the existing Valiant door.

See the 1966 Plymouth Duster Sportwagon proposals made by John Samsen.

While PPG worked on making the glass, Advanced Car Engineering’s John Worthy was brought in to stuff new windows into doors not designed for them, and then make them go up and down flawlessly. Worthy made the 45 inch curved glass work inside those 90 inch curved glass designed 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.”

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; the tail lights had no bezels, and attracted rust. The rear panel caused a high lift-over to the trunk. The flat deck lids had no handles to for closing; closed them by slamming them with their hands on the lip, resulting in creases or small dents. Plymouth rushed a redesigned lid into production, providing a strengthening vertical rail down the center, early in the 1971 model year. 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.

John Samsen with his slant six Duster and boat

From sketch to final design, creating the Duster had reportedly taken all of six weeks! Plymouth division heads were highly confident.

Enter the Plymouth Duster

The Duster concept name came out of an advertising agency suggestion. It sounded performance oriented, and had a bit of humor in it. After all, when you got beat, 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 either 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 working on how to sell the 340 option. The 340 ci V-8 was one of the highest performance V8s ever built by Chrysler; rated at 275 horsepower, some say it had an easy 320 or better. With the 340, the Duster could easily beat the Nova 350 and its Ford equivalent, not to mention going after big game — the big-block cars, including the 383 and possibly 440 four-barrel Barracuda and Challenger.

plymouth duster car photosMilt Antonick drew up a small image of a telephone booth with the door left slightly ajar, with the letters “C K” beneath it — standing for Clark Kent (Superman).  On the engine silencer pad was a 36-inch-square Superman-style “S.” The rights had been secured from DC Comics.

Chrysler-Plymouth Division Assistant General Manager R. K. Brown reportedly thought it was the most ridiculous concept he had ever heard about. 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 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.

valiant duster diagram of the cars

The Duster was based upon the solid and proven Chrysler engineering of the time: unibody construction, front torsion bar suspension, Torqueflite automatic, manual or power brakes (drums, with optional front discs), bench or bucket seats, and, for 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. That was within the territory of the 440 V-8-powered B-bodies.

The Plymouth Duster hits the showrooms

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

Car Life rated the 1970 Duster 340 with a 3-speed TorqueFlite automatic in their March 1970 issue. They obtained 0-100 mph in 17.5 seconds, with a quarter mile time was 14.7 seconds @ 94 mph. Overall gas mileage was 14.8, quite good for the performance and the time. Weight was 3,520 pounds as tested, price $2547.

Some car testers said the Duster tended to understeer. Even at triple digit speeds, though, the Duster 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, a massive increase over the Barracuda, even with two-door Valiants added in. When the 50,810 four door sedans were added in, Valiant broke its previous sales record with a 1970 total of 268,002 units.

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 spend a little to get serious brakes (front discs, power assist, or both). The Duster had a five inch longer wheelbase, 4.5 more cubic feet in the trunk, 11 inches more hip room in the rear seat, 3.5 inches in the front, bigger brakes, more options to choose from, and a far better warranty than the Ford Maverick.

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 looked like the Duster 340, but it didn’t have the 340.

With sales of the 1970 Duster through the roof and seemingly no end in sight to the demand, Plymouth stylists were already hard at work on 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

demon and swinger

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.


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.

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

1972 had been planned for an all-out makeover. The stylists prepared for softer, rounder Darts, Demons, Dusters and Valiants. The decision had been made in 1970. At that time, there wasn’t much money to go around, so the decision had been that there would be no allocation for the 1972 models. It didn’t make much difference to the public. The cars were so popular that they just kept on selling, just as they were. They owned a 30% compact-car market .

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 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 restyled with a more “formal” look for 1973, their last major styling change.

1973 Plymouth Duster 340

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

Chrysler’s famous Electronic Ignition System, phased in during 1971, was installed on all engines late in the 1972 model year. The system dropped the points and condenser, and boosted voltage by up to 35% for better cold weather starting and fewer misfiring. The Cleaner Air System used exhaust gas recirculation, a troublesome orifice spark advance, and an electric-assist choke to return the engine to normal operation more quickly.

duster twister

power disc brakes for 1973 plymouth carsDisc brakes were made standard on all V8s, optional across the board. Power assist was standard with the Duster 340. Inside, mandatory 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. A sliding sun roof was optional. The Special Coupe, in contrast, 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 usury rates for high performance cars; the Duster 340 had 15,731 sales this year, the most ever, but also its high point. Insurers hadn’t gotten around to figuring out just how fast the 340 truly was, keeping the rates out of the skyrocket column. Gasoline availability from the 1973 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, with long lines at stations.

The gas crisis boosted sales of all non-340 Valiants, Dusters, and Darts; there were 380,592 US registrations for the 1973 Plymouth Duster. 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 still 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, and its main target was people used to bigger, more expensive cars, who wanted better gas mileage. The Brougham pushed Plymouth into an easy third place win in the production race. 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 “feature” could easily be eliminated in the Duster by disconnecting the wires underneath the seat. By 1975, that rule had been dropped.

The Dodge Challenger and Plymouth Barracuda ended production in April 1974. The original Barracuda — whose concept was recreated by the Duster — had been the correct answer after all. It might have just been too far ahead of its time.

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.

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.

Plymouth Valiant Duster - cars of 1975

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 upscale compacts that would actually be profitable. Its early publicity gave people a reason to not buy. and sales dropped; though the Brougham was still strong, as fuel-efficiency minded customers, used to the luxury trim in their big Fury or Monaco, could buy them without a qualm. The 360 only sold 1,421 units in 1975, and was dropped at the end of the year.

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

1976 Silver Duster

Hidden among the Valiants, the Duster garnered 34,681 sales that would not come back to haunt Ma Mopar. Two surprises included the Silver Duster package, an appearance and trim scheme, and the more popular, more memorable Feather Duster.

silver duster

The Feather Duster included aluminum trunk bracing, inner hood, bumper brackets, and intake manifold, cutting 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 a surprisingly high EPA rating of 22 mpg city, 31 highway with the automatic and a stunning 24 city, 36 highway with the manual; it was larger inside than many other economy cars, and a fine alternative to the even slower Japanese and more rust-prone imports of the time. The Feather Duster could be well optioned, too.

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.)

1970 plymouth duster

Finally, like all good things, the end arrived. The Duster went quietly 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. With all the uproar, it was easy to forget that the Duster was still around for 1976.

1966 Plymouth Duster Sportwagon proposals made by John Samsen.

Plymouth Twister

Dave Duricy wrote that the Plymouth Duster Twister option package cost $100 and included a large variety of trim and stripes, but did not include any engine enhancements - a sheep in wolf’s clothing. It started up 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 DusterThe Plymouth Duster name continued as a trim line. The Volare coupe was clearly a continuation of the same Duster concept, even down to the optional fold-down rear seat. As Lanny Knutson wrote in the Plymouth Bulletin:

In designing coupes, stylists prefer to move the rear window forward and at a sharper angle to give the car a close-coupled appearance. This, in turn, necessitates moving the rear seat forward to provide sufficient headroom which results in wasted space between the seat back and the rear axle. If the wheelbase is shortened and the axle is moved forward, this “wasted” space can be eliminated and the two-door car is given a more well-integrated appearance. It also becomes lighter and more maneuverable. ... By going to two wheelbases, Plymouth avoided the compromised position of the Ford Granada, a direct competitor to the Volaré Premier line.

volare duster

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; they claimed they had to remove the air cleaner to be convinced only a two-barrel was underneath. The 360 had to be paired with an automatic.

The Duster name was a natural, given that the Plymouth Duster was one of the most successful nameplates ever introduced by Chrysler Corporation at that point, and it finally came back. Sales were not quite as high.

Walt Ronk wrote that the Volare with Duster Package was designated as RPO A42. 1980 Duster production for the A42 cars was just 5,568, while Road Runners for 1980 dwindled down to a mere 496.

Horizon-based Plymouth Turismo Duster

The Plymouth Horizon, engineered in two continents using an award-winning, best-selling Simca as its basis, was a hot seller for years. The Duster name was applied to a car in the Horizon lineup as well, joining the Dodge Charger.

These cars had light weight and an independent front suspension, and one form was particularly successful — the Omni GLHS, which used the cars’ original hatchback form. The Turismo and Charger (TC3 and O24) converted the economy-hatchback shape into a sportier low-slung hatchback-coupe shape. The Duster was merely a trim level, with no changes to the body — not a single curve or stamping was changed from the Plymouth Turismo.

Turismo and Plymouth Scamp

The Plymouth Duster package was launched in 1985, essentially adding a rear spoiler, rallye wheels, and stripes. For 1986, there were three Turismos: base, Duster, and 2.2. For 1986, the Duster added special bucket seats, wheels, and trim to the base model; the Turismo 2.2, with its higher-performance engine, was more formidable than the Duster.

Plymouth Sundance Duster

plymouth sundance

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. It also changed the name from Sundance RS to Sundance Duster.

The Plymouth Sundance Duster was, again, just a trim level; it included the V6 and some 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. This was the only Duster to use a non-Chrysler engine.

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 | Valiant cars | Turismo | Sundance | 1966 Duster Sportwagon drawings | John Samsen Car DVD

340 V8 | 318 V8 | Slant Six | 2.2 Engine | 2.2 Turbo | 3.0 V6

We make no guarantees regarding validity, accuracy, or applicability of information, predictions, or advice. Please read the terms of use and privacy policy. Copyright © 1994-2000, David Zatz; copyright © 2001-2017, Allpar LLC (except as noted, and press/publicity materials); all rights reserved. Dodge, Jeep, Chrysler, Ram, and Mopar are trademarks of Fiat Chrysler Automobiles.

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