Swapped to Muscle - 75 Duster Daily build

[Chambec]

Hello everyone! Here is my build thread, well, more like documentary on the progress of building my new daily that I recently got. I posted in the new member forum not too long ago but here is where I will be post updates to the build.

To begin, I have always been into Mopars for a long time. My first rig was a 84 W150 truck that I got. I have had numerous Dodge pickups for the longest time but never once had a mopar car. I have always wanted one. This came to fruition a couple weeks ago where I had made a deal with my wife that if I were to sell my (at the time) daily which was a 2016 Honda, that I would be able to get a older car to daily and build. I sold the Honda and got the funds to actively search for a replacement daily. For a few weeks I was looking for the right deal. Looked at shell'd out scamps, shell'd out darts, high-dollar roadrunners and chargers, and over-priced barracudas due to sentimental value, etc. Fortunately, my wife kept me in reality while searching or this would be a completely different story lol

Anyways, that is where I found this. A 75 Plymouth Duster that already had a 4-spd swap, a V8 and runs and drives, fairly reliably. Oh and had brakes. My goal and intent is to build this to be as reliable as a modern car, handle like a modern, have more personality than modern cars and more importantly, make some memories with the kiddos.

So with that all mentioned, here are the (somewhat) current specs on the car.

- 75 Duster Body (Factory \6 with AC, Auto, 7.25 rear and very minimal surface rust)
- 70 Duster 318 swap (fairly stock from what I can tell) w/Schumacher mounts
- 76 Aspen A833 (OD) swap w/hurst shifter push-in style
- 70 Duster Steering column (Doesnt have the auto shifter)
- 70 Dart 8.75 w/741 Case - Not sure on the gears though and still 5x4 wheel pattern

Here is my thoughts on the various stages of what I intend to accomplish.

Stage 1: Get running and make reliable
- Work on the wiring as its a mess (turn signals - In progress, headlight dimmer switch, etc)
- Get the gauges working or replace with aftermarket - In progress
- Update cooling system ie Replace radiator as its leaking, hoses, thermostat, etc
- General tune up - plugs, wires, etc
- Update ignition system - HEI conversion for hotter spark
- 8 3/4 BBP swap (Potentially disk brake swap as well) - Going with 8.8 Explorer swap
- Replace wheels and tires as they are like 20-30 years old (at least the rear is lol) - In progress
- Replace carb with Edelbrock 1906
- General maintenance items (belts, fluids, filters, etc)
- Potentially steering components as well - In progress
- Some form of exhaust as there isnt any currently

Stage 2: Performance enhancements
- Front end upgrades which include UCAs, LCAs, Strut bars
- Suspension updates like TBs, leafs, and shocks
- Cam swap w/ timing chain (Maybe a magnum swap if I find a deal) - In progress
- Charging system update
- Headers & exhaust
- 489 8 3/4 gear swap
- Braking system update with new MC and potential disk brake upgrade as well?
- More that I am likely not thinking of

Stage 3: Dream updates
- Potential HEMI swap (Have one on the engine stand now)
- T56 swap

So here are the images of the car prior to any updates done to it so far.

Legend: In progress / Complete / Direction Change/NA

 

[Chambec]

Since getting it in the driveway, the first update that I wanted to do is get the ignition updated. I researched into like Pertronix ignition systems, MSD, etc. But when searching on here, I found out about the HEI conversion using a GM 4-pin ignition module. So after about a week of research, part number gathering and what not, I got the components and wiring to get that done.

So I went with a cheapo GM ignition module from Autozone and MSD 8202 coil just to see if that would do the trick. Got the jumpers connected for the ballast resistor bypass. Hooked up the coil with a new positive wired to the ignition module along with the ground. The current distributor literally had 3 different places that it was spliced together so I replaced most of that with new wire and new connector. Got that new connection from the distributor and ran new wire to the ignition module. I reused the wire to the coil to the ballast resistor as the ignition on wire. At the same time, I figured that with the hotter spark, I may as well get new wires, cap, rotor and plugs. Got those in with the larger gap (I set them to .45) and tested. I was shocked. It started right up and the miss that was there was almost gone. Runs way smoother now.

Since that test was successful, I made up a bracket and reused some old heatsinks from a PC that I had laying around and mounted to the location of the old ECU and ballast resistor. I will update the connections with better connectors here soon as this was mostly for testing to see if it would work.

 

[Chambec]

Since I got the ignition updated and functional, I started to get some of the cooling straightened out so I ordered a new radiator from Champion, part# CC526B, but now I am torn if I want to run the stock clutch fan or move to electric fan(s). I have been reading some threads and now its got me thinking if that is something that I want to pursue.

So now, i am waiting on getting that installed so I can knock it out all at once if I do decide on going electric fans.... hmmm

 

[Chambec]

For a carb, I was playing with the one installed on the car when I got it. No matter what I did, it would have a crazy stumble sometimes, even after the HEI update. So my neighbor convinced me to look into and get a Edelbrock AVS2 1906. I ordered that up and got it today. Got that installed in like 20 mins.

Previously, it had a Carter 9000 series (9626SA) that could have benefited from a rebuild, but the AVS2 looked soooo good.

Anyways, after getting it running, it was almost instantly better. No more stumbling or hesitation.

However, I do have a question on the throttle linkage as it seems like its rather hard or stiff. Not sure if I need to get an adapter or something similar.

Also, one thing that I have to do is still is hookup the electric choke but that shouldnt be too bad to do. I also need to replace the fuel filters as well.

 

[Chambec]

Since getting the car, my kiddos have been really excited getting out there and "helping" me with getting it ready to daily. Its really cool that they are interested in helping me out. On one of the test drives, my shifter got stuck in reverse (which I have to figure out how these work and adjust, rebuild, etc as its really really loose). After getting it jacked up and on stands, they jumped right in wanting to help. Their help was consisting of taking a screw driver and de-greasing the trans but nonetheless, they were helping. Its really neat from my perspective.

 

[Gearhed73]

Looks like you have a good plan and a solid foundation to build on.

 

[MOPAR4Me]

Believe this is what you need for the carb/cable connection.

Duster looks to be in nice shape, great to see your kids involved.

Edelbrock Throttle Lever Adapters for Performer Carburetors 1481

 

[Demonic]

Nice Duster! Black & white interior is cool. Unusual to not have headrests, unless that is a pre Jan 1 69 seat.

 

[dustadude]

Love it, will be following this build

 

[Chambec]

Not too much of an update as I am waiting on parts to come in from Summit.

Believe this is what you need for the carb/cable connection.

Duster looks to be in nice shape, great to see your kids involved.

Edelbrock Throttle Lever Adapters for Performer Carburetors 1481

Thank you!! This is exactly what I needed. I ordered one of these and waiting to receive it.


Over this last weekend, I had to drive to Boulder, CO (nice 2000-mile round trip across 2 days) and on the way back, was able to pick a used (like new though) A-Body 2" exhaust in Helena that would bolt right in. Got most of that installed yesterday but waiting on some clamps to connect the exhaust together. Might have to adjust it a bit on the driver side as it is REALLY close to the z-bar / clutch rod. Will have to play with that.

While under the car, looking at the balljoints and steering... Im really debating on what to do with that... the BJs look absolutely terrible... Thinking about ordering some Upper Arms for the top and some form of kit for the lowers and steering. Then I get a case of the "Might as well's" and start looking at torsion bars.... and lower arms... and strut bars... and brakes... but I digress.

Also, while waiting, decided to bust out the 3D printer and make a keychain for the Duster keys.

 

[Chambec]

Got a bit of work done on it yesterday.

Go the new radiator hoses and some coolant and threw in the new radiator. The Champion radiator fit really snug. For those that are curious, its the Champion part# CC526B. A bit too snug at the top but was able to to get the bolts in the stock location. After getting the old radiator out though, I noticed that it was the "pick-n-pull" radiator. It was labeled with some paint, 77 Volare 6 cyl. Taking a closer look, I can definitely see why the lower radiator hose was leaking... its like 1/2" too small of an inlet for the hose that was supposed to be there. Super glad that I swapped that out.

Since the car was jacked up for the exhaust install, I decided to take the wheels off and check some bushings on the control arms and better inspect the balljoints. Not good. The bushings in the control arms are virtually gone. That is probably why when driving it, it would kinda jerk a small amount to a side and steering really funny. Thinking about what the best option is... Also took a look at the strut bars and the rubber is really dry-rotted out as well, similar to most of the other suspension. Really leaning towards to swapping the uppers out for some of the PST upper controls or the QA1's with the QA1 strut bars for now and just replace the lower control arms with new balljoints.

On a similar topic, I was playing around with some wheels that I had to move from the 14's that are currently on it. Tires and wheels are definitely something that I need to address soon as the current tires are really weather-checked. My current options are some factory 15x7? steel wheels that I can clean up and paint or I also have a brand new set of Vision 85 soft 8's that are 16x8 0mm/4.5 in offset.

Here is the specs of the Vision's - https://www.amazon.com/gp/product/B01M8KKZ8T/?tag=fabo03-20

I am really leaning towards the 16's and get new tires for it. I was thinking for the tires, I would get g-Force Sport COMP-2 Front: 225/50ZR16 Rear: 255/50ZR16 but not sure on the fitment in the rear. I threw the 16's (with 235/70's) on the front and cycled the steering and didnt hit or rub anything.... granted the suspension is at full droop at the moment.

But here is the conundrum that I have.... No matter what option that I go with, I have to swap the rear to go to the 4.5 BBP. I am really leaning towards Dr.Diff Stock axles. But if I go that route, I have to get new brakes. I have read that any backing plates from a 8.25/8.75 with the BBP will drop right in. But I am also looking at the rear-disk swap (10.7"). This is such a spiral effect.

 

[barbee6043]

Great project! Good help too! Watching. I love seeing other people work and spend THEIR $$$ !!!

 

[Chambec]

Little update from yesterday.

Got the parts from summit which consisted of mostly fuel related parts ie Fuel pressure regulator, fittings and barbs, fuel pressure gauge, fuel line, the Edelbrock Chrysler throttle adapter along with some exhaust 2" adapters. For sheer giggles, I setup the fuel gauge to see what the fuel pump was putting out to the carb. It was pushing about 8.5-9 psi... So glad I got the regulator. Got that all mounted and plumbed. Set the PSI to 6.5 on the regulator. Really seemed to stop the richness of the burn. Also got the 1481 Edelbrock throttle bracket setup and made some adjustments on the throttle cable so now that is all good.

After getting that all setup, I took it around the block but noticed that the clutch was really sticky. So this morning, I crawled under it and took a look. The Z-bar/Clutch rod is really making contact to the new exhaust. I attempted to get that adjusted but it really didnt move... Might have to drop it and make some clearance dents. Either that or maybe just shave a bit off the z-bar. Unsure what is the best/easiest option.

While I am debating on the suspension/steering and the wheels/tires, I also have been taking a look at the electrical inside of the car. I need to figure out why none of the gauges work. Like none. I am thinking that it might be Amp gauge related but not sure. The dash lights work when the headlights turn on but that is it. I am not sure why but the fuse panel is all hacked up and thinking that it *might* be related or partially related. I would minimally like to have fuel and water temp to work. Though, I think that a new gauge cluster/gauges might be in order once I really get into it and properly splice the wires back on the fuse panel.

 

[roadrunnerh]

Hello! I'll follow along, I'm knee deep in my '75 Scamp engine swap (and lots more than I planned).
Nice Duster!

 

[Chambec]

Hello! I'll follow along, I'm knee deep in my '75 Scamp engine swap (and lots more than I planned).
Nice Duster!

Awesome! Thank you! Out of curiosity, what kind of swap? While I wouldn't be able to do so for quite some time (due to cost and planning, etc) if I decided to go that direction, but I have a 08 5.7 Hemi on the stand that has 60k miles on it that would be neat to swap into the duster... I was allowed to get it as a replacement for my truck but... if its not acting up or anything....

Great project! Good help too! Watching. I love seeing other people work and spend THEIR $$$ !!!

Thank you! I appreciate it.

 

[abdywgn]

never hurts to have spares...or spares for the spares.

 

[Tanker]

I'm shocked! What you have here is a near clone of my 75 Duster, which is a 318 with a factory three speed transmission, floor mounted shifter, white interior with black carpet, same dash panels, same tail end trim and same Lucerne Poly Blue paint. It looks as though you even had the white vinyl on the forward part of the roof as well. The only obvious difference is mine has bucket seats. I drove my car for years with aluminum rims in the rear and the stock rally rims up front. Nice!

Just out of curiosity, how are your white plastic interior parts holding up? By the time my car was about six years old the A pillar covers were beginning to crumble due to UV rays. I'm wondering if that's a common problem or was something up with mine? It's because of this issue that I traded my white interior for black.

 

[barbee6043]

Some colors of Mopar plastic deteriorate much worse than other colors. Plus I guess the plastic was not as durable in general back in the day!

 

[Gearhed73]

The wire nuts under the dash are always a red flag for me...

 

[DionR]

Cool build! And in my own backyard.

Trying to think of any spare parts I have that could be useful, but coming up pretty blank. I do have a pair of UCA’s with decent ball joints but one is cross threaded and is probably junk after the balljoint wears out. Should be useable, until then, though.

Couple of thoughts;

I would check any BBP axles to see what bearing they use. Many use “Green” ball bearings instead of the factory roller bearings. Some pluses and minuses to both, but I would avoid them for a cornering rig. No idea if they have any durability issues for normal (daily) driving. And I think most rear disk brake kits use them as well. Might be that they are ok, just something for you to be aware of.

You don’t need need lower control arms to replace the LBJ. The LBJ bolts onto the spindle and the stud goes into the LCA. I would look at new TB pivot bushings and bracing plates and just use what you have. Unless you want to spend the money for aftermarket LCA. Might add sway bar brackets if you don’t have them.

Can’t think of anything else, but I am local if you want to look at another 4 speed Duster to compare or something.

 

[Chambec]

I'm shocked! What you have here is a near clone of my 75 Duster, which is a 318 with a factory three speed transmission, floor mounted shifter, white interior with black carpet, same dash panels, same tail end trim and same Lucerne Poly Blue paint. It looks as though you even had the white vinyl on the forward part of the roof as well. The only obvious difference is mine has bucket seats. I drove my car for years with aluminum rims in the rear and the stock rally rims up front. Nice!

Just out of curiosity, how are your white plastic interior parts holding up? By the time my car was about six years old the A pillar covers were beginning to crumble due to UV rays. I'm wondering if that's a common problem or was something up with mine? It's because of this issue that I traded my white interior for black.

The plastic interior parts like the pillars, doors, headliner trim, etc are "ok". Some places they seem to be brittle but mostly just discolored. They are more like a "cream" than a white. Definitely more yellow now compared to the seats.

The wire nuts under the dash are always a red flag for me...

lol I agree. Im guessing that is part of the reason for some of the oddities in the interior lighting and some of the exterior lighting. But I dont have a wiring diagram to check it out. I will be using the one that is on Moparts for a 74 (or 73?) to get a bit of a baseline when I dive into the electrical.

Cool build! And in my own backyard.

Trying to think of any spare parts I have that could be useful, but coming up pretty blank. I do have a pair of UCA’s with decent ball joints but one is cross threaded and is probably junk after the balljoint wears out. Should be useable, until then, though.

Couple of thoughts;

I would check any BBP axles to see what bearing they use. Many use “Green” ball bearings instead of the factory roller bearings. Some pluses and minuses to both, but I would avoid them for a cornering rig. No idea if they have any durability issues for normal (daily) driving. And I think most rear disk brake kits use them as well. Might be that they are ok, just something for you to be aware of.

You don’t need need lower control arms to replace the LBJ. The LBJ bolts onto the spindle and the stud goes into the LCA. I would look at new TB pivot bushings and bracing plates and just use what you have. Unless you want to spend the money for aftermarket LCA. Might add sway bar brackets if you don’t have them.

Can’t think of anything else, but I am local if you want to look at another 4 speed Duster to compare or something.

That is interesting about the green ball bearings. It will eventually become a bit of a corner carver for sure. I would get the tapered bearings if I had a press to be able to install them on the axles. I have been eyeing the stock axle package from Dr. Diff minimally and they install the green bearings but not the tapered bearings.

I will likely need to get new bushings for the TB pivot point... Some of the kits I was looking at for new TBs have that so that would be taken care of at that time. But that would be a later date. I am just looking to get it stable on the road to be a good driver.

Also, it would be great to be able to look at a good running Duster to see what all needs to get done and be used as a reference point for sure. That would be greatly appreciated, in addition, to any parts.

 

[Chambec]

Got a small bit of work done on the Duster today before a thunderstorm rolled in and got rained out. Gotta love working in a driveway.

Anyways, back in 2013 when I was working on my truck, I pulled some axle shafts, drums, and a 489 carrier from a 72 Fury in the junkyard. Since the truck is not anywhere near getting done anytime soon, I decided that I would use those backing plates in prep of the BBP swap in the rear of the Duster. So I got those pulled from the truck, removed the hardware and started getting them cleaned and prepped for a brake rebuild. While doing so, my son noticed I was using some power tools and wanted to help, so him and I took turns cleaning the backing plates in prep for some paint. Got them halfway painted until we got rained out.

Based off of the specs of the rear brakes for the rear of the Fury and the actual measurements, I am guessing that they are the 11"x2.5" variant. I was doing some research on here and that seems to be OK to use on an A-Body. I dont **think** I need to upgrade the master cylinder or prop value but I am not totally sure. Though, if someone has suggestions or thoughts on that, any input would be greatly appreciated on that.

In between paint coats, I was working on getting the Clutch z-bar clearance from the new exhaust. Grabbed a die grinder and dropped the exhaust and took about 1/8"-3/16" of material off at about a 60* angle to get that to clear sufficiently. I got to thinking about why the exhaust was so off when the car that it came from was also a 4-spd car (71 Dodge Demon clone w/ 318) and I think that it has to deal with the driver side exhaust manifold. I am not certain yet as I have not measured but I am thinking that the exhaust manifold from a 70 duster is slightly different from that of a 71 Demon. But I very well could be wrong... or that the z-bar is not the correct z-bar for the 4-spd/Duster. IDK but it is working now.

 

[barbee6043]

I don't think exh manifolds were ever different between auto and stick cars but there are many variances of Z bars!

 

[DionR]

There are a couple of different manifolds, specifically performance and non. The 68-74 340/360 driver side and the 68-71 passenger side are more of a free flowing design with a bigger outlet and flat flanges that require a gasket. Then there are the 273/318 manifolds that have a smaller outlet and a tapered seat at the pipe. For the most part, the left side manifolds look the same, but the right side manifolds look strikingly different between the HiPo and LoPo manifolds. There are certainly differences between the manifolds among those in the same groups, but as a general rule that works.

Not sure you could get the exhaust to bolt up if you had the wrong ones, though.

Z-Bars certainly have potential differences that could cause issues.

 

[Chambec]

Little bit of an update.

Decided to tear into the dash to see what was going on with the gauges. Before starting, I took a look from underneath to see if anything was obvious... Well one thing was. The speedo cable was not hooked up. That is one gauge that is figured out. Started taking off the screws for the dash and worked on the wiper switch and light switch. Got the wiper switch out but not the light switch. Dropped the steering column down a bit and got enough of the dash out to get the plug for the light switch unplugged. Also managed to get the Amp meter gauge wires off as well...

Got the dash out and it just didnt make sense. After reading and looking through similar posts on here... I noticed that a ground was not on the cluster or anywhere in the dash. I thought that there was supposed to be one so I added one. Got it temporarily hooked up and tested with the amp meter temp bypassed. Still nothing. No fuel, temp, etc. Maybe I added the ground to the wrong point on cluster? I am not sure. Im really tempted at getting a new bezel and gauge set and going from there. I guess its possible that the cluster is bad. I will have to do some more research on how to test a cluster.

Also, talked to the wife and got her on board on getting some of the larger ticket items due to "safety" lol. This means that she is game for getting steering, suspension and brakes for the duster. Going over to Dr.Diffs site, here is a breakdown on what I think I should get to meet those "safety" requirements:

• 11.75" Disc Brake Slider Caliper Brackets
• Rotors - Drilled/Slotted/Plated (Pair) - 11.75"
  
• Front Wheel Bearings '73+ A/B/E/F/M/J/R Body
• Aluminum Master Cylinder Kit - 15/16"
  
• Axle Pkg Stock Length Mopar 5X4 1/2" Bolt Pattern (pair)- A-body

Unfortunately, I am not able to get the 10.7" Rear Disc kit as its currently sold out. I am looking at some other kits but not sure which one to go with for the rear disc brake swap. Looked at the eBay kits, SSBC, TSM, ScareBird, Wilwood, Pirate Jack but just not sure which one to go with... Any suggestions? Trying to get something that will fit using the 16" wheels that I have so I am thinking 11" or smaller.