My "new" '74 Duster- or why I need a project like a hole in the head

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rapom65 said:
Well that explains where you've been and what you've been up to for the last couple of months. :thumbsup:
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Yeah I should spend more time doing that and even less posting here.

The T56 is working great, it was totally worth it. I’ve done a few other things along the way since then that I haven’t written up yet. And a couple more things planned here in the near future, though nothing that major and nothing that should pull my car off the road for more than a day or two at a time.
 
That dash, Man I love it, can I send you mine to do the same thing! Great car, you do Awesome work.

Jeff
 
jeffnmo said:
That dash, Man I love it, can I send you mine to do the same thing! Great car, you do Awesome work.

Jeff
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Thank you! And no, you can certainly NOT send me yours to do the same thing. :D Just takes time and patience, I did the whole thing with some sandpaper, rattle can paint, and the DMT overlays.
 
Ok, next installment. Replacing my 11x2.5" rear drums with 11.7" rear disks from @DoctorDiff.

So, this is what I started with, your basic 11x2.5" drums.
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Now, to be completely fair I already installed a set of DoctorDiff axles with disk brake studs. When I did that, I kept the Timken tapered bearings and also installed a set of DoctorDiff's heavy duty adjusters. These things are monsters!!

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This whole process is pretty straightforward. Remove the axle, pull the backing plate, install the DoctorDiff caliper brackets.

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Reinstall the axle, slide the rotors onto the axle, and install the calipers onto the brackets. Making sure to shim as needed to center the calipers over the rotors. Then add the brackets for the brake lines, and put an extra bend or two on the axle hard brake line. I sprung for new parking brake cables as well so I wouldn't have to mess with the old ones or them being the wrong length, they're installed in the pictures.
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The hard part for all of this was I decided to ditch the stock proportioning valve entirely and replace it with an adjustable prop valve. That meant bending a couple new lines. I made a new driver's prop valve to brake line, and just added a coupler to extend the rear line. The passenger side line was long enough I was just able to re-bend it. I also made a nice bracket and mount for the new prop valve to put it in a spot I could reach easily. And bent up some new MC to prop valve lines.

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jeffnmo said:
Nice. Let us know how they work on the road.

Jeff
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So far they're working well! Little different feel than the old drums, less grabby for sure, more predictable. I just did this one a few days ago though, so they're just getting bedded in and I'm still playing with the prop valve adjustment.
 
72bluNblu said:
So far they're working well! Little different feel than the old drums, less grabby for sure, more predictable. I just did this one a few days ago though, so they're just getting bedded in and I'm still playing with the prop valve adjustment.
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since it's not in a location you'll be messing with it as you drive, get a 1/2 tank of gas and try a few hard stops to see if feels good
 
I have the same brakes (and the doctor diff axles) on mine and a stock '70 Drum combo valve, as far as I can remember I'm dropping a very minimum amount of brake pressure and its working well. I have hydroboost which really gives you some brakes right now!
 
goldduster318 said:
I have the same brakes (and the doctor diff axles) on mine and a stock '70 Drum combo valve, as far as I can remember I'm dropping a very minimum amount of brake pressure and its working well. I have hydroboost which really gives you some brakes right now!
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Yeah right now I'm running the prop valve wide open. It actually seems pretty close to balanced already, but I want to make sure I have the pads fully broken in before I do too much adjusting.

I did notice a smidge more pedal travel, changed the ratio of the master cylinder bore to the rear brakes a little I think. So still getting used to some of the changes. My set up is fully manual, but it doesn't take a ton of leg. I like the feel the manual brakes give, it's not super difficult but you definitely have to mean it.
 
Blu, quick question about your rear disk swap. I see you did away with the stock prop valve, did you add a 2lb residual valve to replace the original 10 lb valve for the drum brakes? Or just eliminate it altogether?
Thx
 
fishmarket said:
Blu, quick question about your rear disk swap. I see you did away with the stock prop valve, did you add a 2lb residual valve to replace the original 10 lb valve for the drum brakes? Or just eliminate it altogether?
Thx
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I have the same brake swap and I have the drum distribution block and a wilwood proportioning valve in the rear line only. You will want the adjustable proportioning valve in my opinion. I got some rear wheel lock up the other day and had to take a little rear bias out. No need for a residual valve with disk brakes when the master cylinder is in the stock location. I have an 80's aluminum master cylinder (1 1/8 due to Hydroboost).
 
PlumCrazyChris said:
I really love the build, good work. I'm curious about when your Demon will be all one color?
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Eventually?

It's really not a priority for me. The car works great as is, the original paint is holding up pretty well and as long as it isn't rusting away I don't care. The car is my daily driver at this point and has been for more than a few years, so finishing the paint job would mean taking it off the road.

fishmarket said:
Blu, quick question about your rear disk swap. I see you did away with the stock prop valve, did you add a 2lb residual valve to replace the original 10 lb valve for the drum brakes? Or just eliminate it altogether?
Thx
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I don't have any kind of residual valve front or rear, the height of the master above the calipers is plenty. I eliminated the stock prop valve and replaced it with this adjustable one, although I actually haven't adjusted it very much. I've got like 1 turn on the valve from wide open, but my rear tires are bigger than my fronts so that may be part of it too.

Summit Racing® Adjustable Brake Proportioning Valves SUM-G3906

goldduster318 said:
I have the same brake swap and I have the drum distribution block and a wilwood proportioning valve in the rear line only. You will want the adjustable proportioning valve in my opinion. I got some rear wheel lock up the other day and had to take a little rear bias out. No need for a residual valve with disk brakes when the master cylinder is in the stock location. I have an 80's aluminum master cylinder (1 1/8 due to Hydroboost).
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Yup, agree. I haven't adjusted mine very much but I really couldn't have known what it would need before the install. I run a 15/16" master cylinder from DoctorDiff but my brakes are manual still.
 
72bluNblu said:
Yup, agree. I haven't adjusted mine very much but I really couldn't have known what it would need before the install. I run a 15/16" master cylinder from DoctorDiff but my brakes are manual still.
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I have "only" 275 width rear tires, had to get on the brakes hard and the rear wheels skidded for about 20' (actually left marks on the road!), so I made a pretty big adjustment. Now I get some front end dive. It's probably okay now. At the beginning they didn't really have a lot of output but since they have a couple thousand miles on them now the output is up. You don't really use a ton of brake driving on mostly 45 mph roads and having a stick shift, especially this one because it compression brakes well. On my other manual cars I get a wear rate where my brake pads would wear out in about 110,000 miles, of course the winters kill the rotors before you can get there usually.
 
goldduster318 said:
I have "only" 275 width rear tires, had to get on the brakes hard and the rear wheels skidded for about 20' (actually left marks on the road!), so I made a pretty big adjustment. Now I get some front end dive. It's probably okay now. At the beginning they didn't really have a lot of output but since they have a couple thousand miles on them now the output is up. You don't really use a ton of brake driving on mostly 45 mph roads and having a stick shift, especially this one because it compression brakes well. On my other manual cars I get a wear rate where my brake pads would wear out in about 110,000 miles, of course the winters kill the rotors before you can get there usually.
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Yup, I do a fair amount of engine braking with the T56 and 9.8:1 compression. I run 295's out back and 275's up front too so that changes the bias a little. I could probably dial the rears back a little more, they definitely have worn in a bit and grab harder than they did when I first installed them.
 
I'm glad I found this thread, I had the similar build thread from the Protouring Mopar site bookmarked. Since it's been vaporized into the cloud a lot of cool Mopar stuff has gone away. Great car and build thread, Thanks!
 
This still ranks as one of the best driver DIYS threads for A-Bodys. I'm hopeful to get my Duster out of Body Shop Hell in the next month; I guess I'll have to update my own thread!
 
DionR said:
Been over a year since the last update Blu. Time for mods!
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Sorry guys, not much been going on. Mostly just driving it. Biggest things I've done since I posted was removing the tire well in the trunk, installing a flat floor and installing a '68 Charger fuel tank. Ended up being more work than advertised with modifications to the rear crossmember being needed. The extra few gallons of fuel is nice though and it tucks the tank in a little better in case I decide to do a rear diffuser later. Plus EFI tanks for '68 Chargers are easier to find if/when I go the EFI route. I was hoping the sending unit would be more accurate without that big tire well step but that didn't really work out, the new sender is pretty much as bad as the last one. It also gives more room for the tail pipes.

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I also installed a console finally, I welded the mounts on when I installed my T56 tunnel but hadn't redone the console yet.

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I thought the early tanks were 18 gallons. Those are a direct fit, right?
The Charger tank is 19. I can see the advantage of more exhaust clearance though.
That Pistol Grip looks like a natural fit for these cars!
 
Nice, do you have more pictures of the trunk floor and fuel tank install process?
 
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