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340 4-Speed Project: 1970 Plymouth Duster

On September 29, 1969, Plymouth rolled out a sporty new version of its popular Valiant model. With semi-fastback styling and available V8 power, the new Duster was designed to compete with the Chevy Nova, as well as popular compacts like the Ford Maverick and AMC Hornet. Our feature vehicle is the performance-oriented 1970 Plymouth Duster 340, said to be mostly original and one-family owned since new. Located in McKees Rocks, PA, it can be found here on eBay.

The highlight of the Duster 340 was, of course, its powerplant. Offered as part of a $400 option package, the engine included a four-barrel carburetor and was backed up by either a three- or four-speed manual or a three-speed Torqueflite automatic. Also included in the performance package was dual exhaust, a 3.23:1 rear axle, heavy-duty suspension, and front disc brakes. With a conservative rating of 275 horsepower and packing 340 lb-ft of torque, the engine provided more than enough grunt to power the lightweight compact from 0-60 in 6.5 seconds, beating a 1970 Corvette 454 by half a second. Our feature vehicle has been stored for over 25 years, but it is reported to currently run, drive, and stop. While the engine itself appears to be complete and mostly original, there are signs of significant rust on the inner fenderwells.

The 340 package included a special instrument panel with a tachometer and 150mph speedometer, and both appear to be present on our feature vehicle. Although the bucket seats are in rough shape, they provide a good base for reupholstery. The rear seat however appears to be near mint and is currently providing storage for spare parts, including a water pump and hoses. The driver’s side floor pan clearly needs replacement, but a patch panel appears to be present in a listing photo of the trunk. While that may seem like a big project, the rest of the interior floors look surprisingly solid. The new owner will also need to track down new door panels as well as rear panels. Still present and accounted for are the requisite four-speed shifter and third pedal, a plus for any enthusiast.

Plymouth produced 217,192 Dusters for the 1970 model year, with just over ten percent of those being 340 models. While this example may have some rust issues, it is the more desirable model for collectors, checking all the right boxes. It may be too rough to drive as is, but some time with a welder and some fresh sheet metal could put this A-body muscle car back on track to a new life.


  1. erik johnston

    easy restthe cowel,top of fender,doors and around thegutter.I would love this one-but i dont want any distractions, i do love this one though. I wonder what the finial price will be.

    Like 2
  2. Sam Shive

    Another (M)ostly (O)ld (P)arts (A)nd (R)ust. McKees Rocks, PA I bet this has more rust than you can see. Pull the Vin and the 340 and fins another body.

    Like 1
    • Dave

      I agree. McKees Rocks is just west of Pittsburgh and the car is subject to everything they were throwing on the roads and in the air. It’s upwind of Neville Island, former home of Shenango, a company that made coke and coal byproducts.

      Like 0
      • Llouis200

        McKess Rocks is Pittsburgh and you are correct about having everything under the sun thrown at it. I would have to see that car first before putting any money on it. They used to put there cars away for the winter so it may be worth looking into.

        Like 1
    • bone

      No more rotted out than any Mustang or Camaro that’s spent its life in the rust belt . Its a 51 year old used car . We get it that you hate Mopars and what they sell for , but maybe just to be fair, the next time a rotted away Mach 1 is posted and selling in the 5 figure range you can post F (ull) O (f) R (usty) ;D (ents).

      Like 15
  3. erik johnston

    I like this a lot,its just to bad the rust is so bad on the underside-still worth restoring.i like the CORRECT blackout treatment on the hood ect. Being so stock is a huge + I would bid, but i,m so close to getting my 71 twister done that I would be distracted. Mine is painted orig. fc7. int. is compleatly done just
    needsinstalled. Engine the engine,trans need installed(3spd numbers match, 8 3/4 also) very little rust ever.

    Like 2
  4. Donnie L Sears

    Speaking of a four-barrel carb. I don’t know of any 340’s that were ever built with a two-barrel carb.

    Like 3
    • Dave

      It was common to replace a blown up 340 with a 318. There are web pages that tell you what to look for on a genuine 340.

      Like 0
      • Buddy

        For starters, an “H” in the VIN will do. A 318 car had a “G”.

        Like 0
  5. Matt

    The rust on this car is bad. Nothing i like better than a 340 4 speed duster but if you really look close at the pics of this car it’s rotted through EVERYWHERE. Yes its repairable, yes it could be a beautiful car. Who cares if its a 2 owner or 20 owner car, it makes no difference in value to me. Just know going into it your going to spend a mint on metal work if you can’t do it yourself.
    Somebody will buy it and I hope they have the funds to bring it back. My second car was a silver 340 4 speed with the flat black hood and 340 stripes on the sides. LOVED it.

    Like 2

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