72 Plymouth Duster slant six build

[69 Charger 440]

Thought I'd post up my 1972 Plymouth Duster build I have going that was purchased about 2 years ago. It started life with a 225 slant six, 904 auto trans, 7.25 rear end, a/c, power steering, and manual drum brakes. Car fired right up and drove pretty decent but the tires were well beyond any usefulness and the brakes were nonexistent. Interior was a mess, had the funk of mice living inside but it was just about all there. Suspension was toast, nothing had been replaced in many years but I was ok with that as I like to add newer parts where needed.

To start off I cleaned and then cleaned some more. Pressure washed everything a few times just to clean off the grime and added some paint and undercoating to the undercarriage for protection. The floors were almost perfect, aside from a 3” spot on the driver floorboard there was no rust at all. It took a while to clean out the mice nests but it cleaned up enough that you could actually sit in it and breathe. Anything that looked like the start of surface rust got covered in rust encapsulator so I shouldn’t have any issues pop up down the line.



To get it on the road it first needed new tires. I didn’t want to just throw new tires on the 14 inch rims so I Got a cheap set of 18x7’s and 18x8’s as a temporary solution. The plan was to swap over to the large bolt pattern, front is an easy fix with new brakes but the rear was a problem with the small bolt pattern 7.25 rear so I used some adapters to get by. I liked the style but the rears didn’t fit properly but they worked to get the car drivable.

[69 Charger 440]

Now it was suspension time, this is probably my favorite part to work on especially when adding nice new shiny parts. The main goal with the new parts was to make the car comfortable to drive and not a stiff race car feel but also something that is not going to get out handled by a minivan. I tore the whole front end apart and added QA1 upper control arms, QA1 strut rods, QA1 steering rods, hotchkis front sway bar, hotchkis/fox shocks, Dr. Diff cobra style 13” brakes, new master cylinder, brake lines, new pitman, idler arm, and lower control arm bushings. Also boxed the lower arms while they were off.

I did add a set of 1.03 torsion bars but they made the car sit like a 4x4. No matter how I installed them (arm at full drop/ride height/and even up) I couldn’t get the car to sit properly so they came off and the stock slant six bars went back in for now. I think the clocking is wrong but I’ll get a proper set from Firm Feel eventually. I also have a set of Hotchkis subframe connectors that need to go in.

[69 Charger 440]

Next was to clean up the engine bay. I did a compression test on the motor and it turned out to be in great shape so for now it is staying in the car. No smoke, no leaks, and it ran smooth. Had absolutely no power but it is kinda fun to work on. So, I started pulling off parts to clean up and paint. Removed all the a/c parts since they didn’t work and removed everything else that wasn't used to clean it up. I tried to match the color in the engine bay but it came out a little darker than expected but I can live with it. Painted the motor and intake while it was apart and the engine bay started looking sanitary.

New gaskets all around, changed all fluids, adjusted the valves, cleaned up the carb, new valve cover, new ignition parts, and it was running smooth. The radiator fell apart while removing it so a new Champion aluminum radiator went in its place. Bummer here is the new radiator is a little thicker so the stock mechanical fan didn’t fit with the clutch. So I added an electric fan up front and it has been cooling nicely.

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Then I tackled the paint. A full repaint was out of the question so I wet sanded it first and then went to town with the DA polisher. Paint came out pretty good and brought some of the shine back. The problem is when I got it I painted the rear quarters to fix some bad paint. it looked fine when it was faded but once it was shined up you could really tell the paint doesn’t match. Eventually it will be corrected but for now it will be mismatched.

[69 Charger 440]

The interior was a mess so everything came out and went and all new stuff went in. Seats, carpet, headliner, dash pad, steering wheel, door panels, stereo, dynamat all around and a bunch of other smaller parts went in. I didn’t see the point in recovering the bench seat so I went with a set of Corbeau Sport seats in leather for a more comfortable ride. And the rear seat got new foam and a cover from Legendary.

[69 Charger 440]

Some more photos

[69 Charger 440]

About six months later I decided I was done with the stock gauges and went with a set from Speedhut. I really like these gauges. You can pick any color combo you want and they are easy to install. I went with a grey/white set that light up blue at night. I like that you can set warning lights and the fuel gauge can be calibrated to any sender so no more issues with the repro sending units.

[69 Charger 440]

I also knew I wanted a console with cupholders. The stock console aside from being expensive doesn’t really have the look I wanted. So I looked at newer cars and got a 2017 Challenger console and threw it in there. Fit almost perfect so I welded in some mounts and in it went. The only issue with it was the front of it housed the heater controls which I wasn’t using. So I filled in the area with ABS plastic and then mounted a clock, a/f gauge, and a trans temp gauge from Speedhut. These gauges are thin so they fit inside perfectly. I added in a Hurst shifter and made a cover so it looks right at home. Still need to pull the column and replace the collars so I can get rid of the column shift look.

[69 Charger 440]

As the new parts went in the old wiring was showing its faults. I installed an American Autowire kit in the Charger and really liked it so another kit from them was on order. With the kit I had to get a new one wire alternator but the install was smooth and everything worked out great. While working on the electrical I added all new LED lights all the way around, HID headlights, and swapped in a sharktooth grill.

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[69 Charger 440]

Then I started having carb issues. It was dumping gas into the engine and I couldn’t find rebuild kits for it. Rebuilt carbs were a couple hundred bucks so I decided to go with a 4 barrel carb so I could get replacement parts easily. With the new Quickfuel carb I had to get a new intake from Offenhauser and kickdown linkage from Bouchilon Performance. Carb is way to big but it did give the throttle response a much better feel. Also the repro mopar ignition module crapped out so I installed an MSD box I'd been holding onto.

[69 Charger 440]

Next was the rear end. The 7.25 stock rear was garbage along with the leaf springs. So a new setup was built. Got a Sure Trac center section with 3.23 gears, axles, the housing, rear brakes, and brake lines from Dr. Diff. Cass has been great to work with and everything has been top notch. Also got a set of Hotchkis leaf springs and the new rear went in. Had a local shop build a new driveshaft and it all went in nice and easy.

[69 Charger 440]

Now that I had the rear end finished, I could order a wider set of wheels that fill out the back better. Duster’s have a huge lip on the rear so I trimmed about ½” and rolled the front lips to fit as much tire as possible.

[69 Charger 440]

more pics

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While the wheels were on order, I decided that I like being broke and replacing perfectly good parts so I bought a set of Viper calipers for the front. The car stopped fine but now should be on another level.

[69 Charger 440]

Ended up fitting 18 x 9’s up front and 18 x 9.5’s out back with 275’s on all 4 corners. I’ve always liked trans am styled cars so I went with a mini lite style wheel from a local company here in the bay area.

[69 Charger 440]

I still have a few things in the works but this is where it is at as of now. I have a new exhaust, rear sway bar, gas tank and lines, hoodscoop, and subframe connectors to install. I also need to have the quarters repainted. I can’t get a good match on my own so I need to take it to a shop to have it professionally done. I also have 2 sets of stripes, one is the stock solid stripe and the other is a Cuda T/A style stripe. Not sure which one but I’m leaning towards the T/A stripe which will go on after the paint gets fixed. The plan is to drive it as is for a couple years to save up and then take it to the next step... 408 stroker small block or 6.4 Hemi with side exit exhaust to complete the trans am look. Or Torquestorm has a supercharger kit for the slant six.

Thanks for checking out the build.

[HotWheelz]

Fantastic Build!

Beautiful!

I just like the whole profile of the Duster.

Absolutely gorgeous engine bay shot!

Slant sixes are great engines.

My vote is for the slant six and the super charger!

[RMMiller]

What a transformation on the interior, it looks great!

[mean buzzen half dozen]

Nice work & great to see a fellow inliner.
Stay with a slant six & either turbo or supercharge it.. You will get a lot more looks and people will be wanting to hear all about your build.
Take the car to car hops & people will flock to your car.

[1965gp]

Love this build- fantastic transformation and cool to see something different. I agree on keeping the slant 6 if it is feasible.

Who did you buy the wheels from? I am looking at the reproduction super lites but they only go up to 17”

[69 Charger 440]

Thanks guys!

The slant has been fun to work on. Everything is easy to get to and has plenty of room in the engine bay to work with. It is great as an in town cruiser but for the freeway it needs some more power.

I do get a lot of people who ask what engine is in it and are surprised when I say its a slant.

Wheels are from ET Mags.

http://www.etmags.com/

[Twentyover]

Then I started having carb issues. It was dumping gas into the engine and I couldn’t find rebuild kits for it. Rebuilt carbs were a couple hundred bucks so I decided to go with a 4 barrel carb so I could get replacement parts easily. With the new Quickfuel carb I had to get a new intake from Offenhauser and kickdown linkage from Bouchilon Performance. Carb is way to big but it did give the throttle response a much better feel. Also the repro mopar ignition module crapped out so I installed an MSD box I'd been holding onto.

Man, I saw the build and thought,
What a great engine to put a manifold for triple DCOE's and either bike carbs or Borla DCOE ITB's. But it was not to be....

:(

But then I thought,
He's keepin' the Leanin' Tower of Power



So I guess both happy and sad...