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...

[GoodysGotaCuda]

Looks like you're doing a great job piecing the car together, I like it!

I have to stray from the pack and say lose the Slant. They take a ton of money to make power that isn't close to today's standards.


How's the lateral support on those seats? I'm about due to either recover my factory seats or replace them with something aftermarket.

[69 Charger 440]

Looks like you're doing a great job piecing the car together, I like it!

I have to stray from the pack and say lose the Slant. They take a ton of money to make power that isn't close to today's standards.


How's the lateral support on those seats? I'm about due to either recover my factory seats or replace them with something aftermarket.

Yeah the slant has no power but it's kinda fun to putt around in. One day I swap something big in there but for now its going to be a slow cruiser.

The seats aren't too bad. They have some extra bolsters but aren't too aggressive. I have race style seats in my charger so I wanted something geared more towards comfort for the duster. For around the town cruising they are perfect and anything offers better support than the old stock mopar seats.

[mean buzzen half dozen]

Some slant 6 vids
https://www.youtube.com/watch?v=ZPm0POxQuNk

https://www.youtube.com/watch?v=mAoUnwk-S40

https://www.youtube.com/watch?v=bmzFARNMv2c&list=PLbMpkkuEMeJ9IueHTW5w_G7bbopeb88cE

https://www.youtube.com/watch?v=ZM8rLyt6fzI

[69 Charger 440]

Been a while since I updated this thread so figured I'd post up on the items crossed off the list over the last year or so.

Always had a decent sized transmission leak and always thought it was the pan gasket but turned out there was a crack in the case! Thought about just replacing the case but figured it would be better just to get a new transmission. Luckily Cope Racing had a slant six case in stock and the order was placed. Took about a month to get but the swap went smoothly. Only issue I had was I couldn't get the torque convertor all the way seated because the tabs had shifted in shipping. Once that was fixed the old one came out and the new one dropped right in.201709201708201707

[69 Charger 440]

While I was waiting on the new transmission I decided to work on the paint and match on the lower quarters. Got the correct Amber sherwood green paint mixed up and pushed it in the garage. Came out pretty good and am happy with the results for a driver.
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[69 Charger 440]

Got the hotchkis rear sway bar in and a new stainless gas tank installed.
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Current project is a new TTI exhaust. I got started on it the other day and welded in an 02 bung but ran out of time getting the rest of it in. So hopefully sometime this week I can button it up.

Really wished I painted the exhaust manifold when I had it off. Looks like crap next to the new exhaust. It'll happen eventually.201721201720

[69 Charger 440]

Also installed the hood scoop and hood pins. Didn't want to just cut a huge hole so decided to cut three 3.5" holes and make an aluminum plate with some dimple die holes to clean it up. I'm happy with how it turned out. Now just need to repaint the underside of the hood.

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[68Formula]

Looks great!

[69 Charger 440]

swap out the steering box for a borgeson unit. Install was pretty smooth but I did have to shim it a bit to line up cleaner with the steering column. Has a much nicer feel now rather than the over assisted stock box.

Also while the column was out, I gave it a freshening up with some a coat of paint and swapped out the collar for a floor shift unit. Now aside from adding a heater box the interior should be almost finished.

Another item that was bugging me was the electric fan up front was louder than the motor! So I added back a standard fan and used made a temporary shroud. Cools great and if it does get hot I have the electric fan as a backup that will turn on at 210 degrees.

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[69 Charger 440]

Here's a couple shots I had from a while back. I'm wanting to get the front end down another half inch or so but I'm sure that will cause some rubbing issues. But it's cruising nicely and has been a fun around the town cruiser. But definitely needs a little more power.

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[69 Charger 440]

Finally got around to adding in the subframe connectors and will eventually do the fender and core support braces to strengthen it up. Also finally got a performance alignment done. Ended up with +5.75 caster and had to go with -1.5 degrees on camber. Anything less on the camber and it would rub slightly on real hard cornering. But the tires will probably age out so not too worried about the extra wear. All I care is that it drives smooth now. Here's a couple photos from the last few months.

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[69 Charger 440]

Another project I did was another cleanup on the paint. I left some sanding marks from when I painted it so figured it was time to properly clean it up and give it a proper polish. Once it was nice and shiny I did a ceramic coating to keep it protected. But after doing it I actually prefer a good sealant and wax. The wax just has a better feel to me over the special coatings. But it is nice and shiny with the coating, just hopes it lasts as long as they say.

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[69 Charger 440]

Got around to pulling the hood the other weekend and stripped the old paint off and gave it a new coat. Always had some rattles so I figured there was some junk in the gaps but turned out to have about 50 acorns stuffed inside. Damn pests! So it was a good thing to pull it. Also added in some heat/vibration material to quiet things down and installed some mesh screens on the hood scoops while the paint was drying.

I want to keep the chrome valve cover but without any baffles the oil spilling out at higher RPMs is bugging me. So installed an oil breather/catch can to see if it helps. If not the stock valve cover is going back on. I do need to replace the valve seals so this is just a band aid solution for now.

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[69 Charger 440]

A couple other recent photos.
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[bkbkbk]

Wow, this car has come together so well! Great color match on the paint!

[jaybee]

You've brought this car a long way by doing one job at a time. Looking good!

[Bjkadron]

This is a fantastic build. Everything looks just right! Love the minilites. Mind if I ask what the front spoiler is? Also what backspacing are your wheels and what tire size did you end up with?

[nickcarlson]

Hello, Can you tell me where you got the gauge panel from for this Duster? I have the same one and need the aftermarket gauge panel...Called Speedhut, but they only have the gauges and not the panel. Thanks Nick

[69 Charger 440]

This is a fantastic build. Everything looks just right! Love the minilites. Mind if I ask what the front spoiler is? Also what backspacing are your wheels and what tire size did you end up with?

Thanks! The spoiler in all the photos was just a basic 69 camaro spoiler, I have switched though to a 69 charger spoiler from Spoilers by Randy. Didn't take much to make it fit, just a little cut to slide over the radiator support brace and it fit right in.

Wheels are 18x9 up front with a 6.25" bs and the rears are 18x9.5 with a 5.25 bs. Tires are 275/35/18s all the way around. Took some trimming and rolling the fenders to make fit. It does rub a bit so I might go down to a 265/35 on the fronts when I have to replace the tires.

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[69 Charger 440]

Hello, Can you tell me where you got the gauge panel from for this Duster? I have the same one and need the aftermarket gauge panel...Called Speedhut, but they only have the gauges and not the panel. Thanks Nick

I got mine from classic dash. Fits decent but the wiper switch didn't fit right anymore as the hole is different from the stock one.

https://classicdash.com/product/1970-76-mopar-a-body-dash-panel/

[nickcarlson]

I checked out classic dash and they said that one would not fit a 1972 Plymouth Duster with the rectangle MPH gauge panel... Must be the "square" one? Was your stock/OEM MPH gauge square or rectangle? Thanks Nick