Carol Duckworth, courtesy of Mecum Auctions
  • Rotisserie restoration
  • 408-ci engine upgrade
  • Automatic transmission
  • Light blue cloth interior
  • Bench seat
  • Cragar wheels
  • Original front and rear seat included
  • Engine upgrade receipts

SCM Analysis


Vehicle:1970 Plymouth Duster
Years Produced:1970–76
Number Produced:192,375 (non-340 Dusters)
Original List Price:$2,172 (Slant-6 coupe)
SCM Valuation:$31,500 (1971 Demon 340)
Tune Up Cost:$250
Chassis Number Location:Dashboard, decal on driver’s door, fender tag
Engine Number Location:Partial VIN on block above oil-pan rail
Club Info:For A Bodies Only
Alternatives:1970 Chevrolet Nova SS, 1971 Ford Maverick Grabber, 1971 Dodge Demon 340
Investment Grade:C

This car, Lot F153, sold for $31,900, including buyer’s premium, at Mecum’s Chicago 2018 sale on October 26, 2018. It was offered with no reserve.

This car was sold as part of the Dan Houpt Collection and holds a special place within a small assemblage of classic Mopar muscle cars.

Dan was a lifelong Mopar enthusiast. Over a short period of time, he managed to collect a small but wonderful array of small-block and big-block Pentastar warriors from the golden age of the muscle-car era.

Dan found four beautiful examples, which he doted on from 2014 until he passed away this past August. This 1970 Duster was the second one he bought. Unlike the others, this one was set up to go without worries of damaging or breaking rare parts. It’s a hot rod through and through.

A hot Valiant

Speaking of hot rods, Plymouth’s design staff pulled a fast one on the Dodge Boys in 1969. With their substantial budget for retooling the Valiant, they decided to create a semi-fastback hard top. Making their own exclusive body, Plymouth created a niche market for themselves. They re-skinned the car using the sedan wheelbase, and from the cowl back, they created a sensational swoopy semi fastback with generous interior dimensions. Dodge saw the Duster in fall of 1969 and howled all the way down the hall to Papa Robert McCurry. The end result was that by 1971, Dodge gained the rights to the same tooling dies. They debuted their own Dodge Demon model that year.

If you wanted speed, Plymouth sold their hot 340 with a 10.5:1 compression ratio and your choice of the base 3-speed manual, optional 4-speed manual or the 727 TorqueFlite automatic. The 383/440 GTS packages were gone by 1970, but Plymouth offered a 360 Duster package later in the decade, which made for a real sleeper when set up correctly.

For competition, the Duster had just Nova SS 350s, Maverick Grabber 302s and Gremlin X 5.0-Liters to deal with — Plymouth virtually had the field to themselves. But factory 340 Dusters were gone by the end of 1973.

While finding a genuine Duster 340 isn’t hard, what’s left now are expensive restorations or rough cobs. A numbers-matching 340 from 1970–71 is worth too much now to bash on the street.

Stock or modified?

Fortunately, Mopars are very popular in both stock and modified form. A fresh hot rod gives you the best of both worlds: tire-frying power and original looks with modern touches like power rack-and-pinion steering, aluminum heads, electronic ignition and fuel injection if you want to really be up to the minute. Something like that can be driven anywhere. With a slant-6 or 318 donor shell, there’s no fear of destroying the value of a rare original 340 car either by accident or through irreversible body modifications.

That said, building a hot rod Mopar — especially using a popular model like the Duster — isn’t a cheap affair. Finding a clean, rust-free body, getting the engine and transmission set up with your favored goodies, custom paint and interior work all adds up to big money. That’s why this car was such a deal. The selling price can only be matched if you’re willing to write off your labor and time.

The market for performance-modded Dusters is stable and healthy. Unlike Ford and GM, Mopar didn’t forget over-the-counter high-performance parts sales after 1971. Instead of the parts collecting dust in dealer bins across the nation, Chrysler assigned new parts and launched Direct Connection to sell them.

The old Hustle Stuff and Scat Pack goodies were carried over, given new numbers if necessary and added to newer competitive parts that kept the little-guy racers and bigger teams in the victory lane. Tips on builds and track setups were available to Joe Leadfoot via their Direct Connection racing manuals issued in 1976 and updated frequently. They had all the info needed from Mopar gurus like Tom Hoover and Larry Shepard.

The Direct Connection program accelerated through the 1980s, and as such, Mopars have a long history of factory-sponsored modifications that were done right and up to the minute. The payoff came in victories at the strip and desirability when the time comes to sell. Thanks to Direct Connection, modified Mopars aren’t as hard to sell as other brands of ’60s and ’70s muscle cars.

Two markets

There are two Duster markets: one for low-production 340 sports coupes and one for 318s and Slant 6s.

Slant-6 Dusters were mass-produced from 1970 to 1976. The prices range widely depending on the quality and depth of a build. A $30,000 modified Duster is fairly common, but it could range from a no-frills bracket racer that’s all engine to a street-strip car with some show and go. Finding one completely done to consistent high standards isn’t easy. Often, money has been poured into the driveline, leaving the interior or paint- and bodywork behind.

On the other hand, the big-money rides are the 1970–71 factory numbers-matching 340 Dusters. $40,000 isn’t unusual for one with the cool extras such as High Impact paint, Rallye wheels, buckets and console. The 1972–73 models are more affordable, but for how long?

That’s why this car’s a bargain. It was rotisserie restored with a lot of love, and it shows throughout. Some suspension work was done as well, as the shock-absorber mounts have been relocated. The dashboard is custom made, the upholstery is new custom cloth and interior paint is done to a much nicer standard than factory. Even the body decals were custom made to show off the stroker small-block build. The Mopar black-crinkle valve covers, aluminum radiator, custom floor mats, Hurst shifter and Cragar SS mags are all top-shelf items typical of a quality hot rod.

A look at current sales of similarly equipped cars shows this one to be right in the ballpark in terms of values for modified A-bodies. With a price spot-on market, this was both a great buy and a good sale for a car that can be used without worry.

(Introductory description courtesy of Mecum Auctions.)

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