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

[moparmat2000]

I love the way you intergrated the rallye dash, and bodyworked thr glovebox trim into making a finish corner. I always hated the standard A body dashes from 72 up. Always looked old people looking to me.

Also love the execution of the Afco leaf spring sliders on the custom brackets.

Overall very cool project. Love it.

Matt

 

[72bluNblu]

Very cool! I like how you came up with a clean way to mount it without having to cut up the car.

Thanks! It was the quick and easy way to do it. I hadn't mounted sliders before so I wanted a reversible way to do it in case my geometry didn't work the way I thought it would. I may notch the frame extensions on the next go around to lower the car a little more, my car is pretty far from stock already.

I could've swore you were the one who notched you frame to set the sliders up higher to lower the rear!! Must've been someone else...

Figured out it was younggun2.0 that notched the frame.

Yeah it was younggun. He has a 3" spring relocation, so his sliders are notched right into the frame rail. Mine are only offset a 1/2", so they stay under that frame extension. The frame is easier to reinforce, and Younggun2.0 did a great job on his, but he still had to section and raise the frame extension. I think I can channel the slider into the frame extension close to a 1/2" before I have to worry about the clearance between the head of the slider bolt and the frame rail. I think. So I may do that yet.

I love the way you intergrated the rallye dash, and bodyworked thr glovebox trim into making a finish corner. I always hated the standard A body dashes from 72 up. Always looked old people looking to me.

Also love the execution of the Afco leaf spring sliders on the custom brackets.

Overall very cool project. Love it.

Matt

Thanks! Yeah I'm not a fan of the later standard dash. Also not a fan of the broken rallye dashes, and they always break on that dog leg that goes out to the glove box. So it worked out great because broken rally bezels are a lot cheaper than good ones, and because my dash frame was converted I didn't have the extra mounting holes for the dogleg or the glovebox trim anyway.

 

[racerjoe]

I have been undecided about the sliders and also have the offset shackles. I was thinking if I did do it, I would fab something very similar to what you did. Curious to your thoughts on them. Worth the work?

 

[fez440]

once you get the digi tail lights installed id be interested in seeing the difference they make. what is the benefit of the sliders on the leafs?

 

[72bluNblu]

I have been undecided about the sliders and also have the offset shackles. I was thinking if I did do it, I would fab something very similar to what you did. Curious to your thoughts on them. Worth the work?

It depends on what you're doing. It's probably not a difference you're going to notice driving around town. Honestly, one of the reasons that I did it was to lower the rear of the car. Because of the way I did the brackets, the car sits about 3/8" lower. I was hoping for a little more, that's about what I ended up with.

once you get the digi tail lights installed id be interested in seeing the difference they make. what is the benefit of the sliders on the leafs?

Hopefully I'll get them installed relatively soon. I'll try to do a write up on the installation with before and after pictures.

As for the sliders, the idea is two-fold. Shackles force the spring to travel in an arc, which doesn't necessarily track the movement of the suspension. The other is that the shackle bushings provide more than a little resistance to the movement of the spring, so, binding. The idea of the slider is that the spring eye moves with almost no resistance, and moves in a linear fashion, which is what the spring wants to do anyway. So, the spring reacts faster and without binding and the suspension works better.

Ideally, the slider would be mounted at a slight angle so the spring movement would track properly. The AFCO's don't really provide for that unless you build it into the mount. Calvert makes a set that has the angle built in, so you can mount the slider flat. These are the Calvert's, you can see the small angle on the track. I didn't find out about the Calvert's until after I had bought and installed the AFCO's.

 

[Abodybomber]

It depends on what you're doing. It's probably not a difference you're going to notice driving around town. Honestly, one of the reasons that I did it was to lower the rear of the car. Because of the way I did the brackets, the car sits about 3/8" lower.



Hopefully I'll get them installed relatively soon. I'll try to do a write up on the installation with before and after pictures.

As for the sliders, the idea is two-fold. Shackles force the spring to travel in an arc, which doesn't necessarily track the movement of the suspension. The other is that the shackle bushings provide more than a little resistance to the movement of the spring, so, binding. The idea of the slider is that the spring eye moves with almost no resistance, and moves in a linear fashion, which is what the spring wants to do anyway. So, the spring reacts faster and without binding and the suspension works better.

Ideally, the slider would be mounted at a slight angle so the spring movement would track properly. The AFCO's don't really provide for that unless you build it into the mount. Calvert makes a set that has the angle built in, so you can mount the slider flat. These are the Calvert's, you can see the small angle on the track. I didn't find out about the Calvert's until after I had bought and installed the AFCO's.

These , should be interesting... How was the AFCO quality ,& did you like the craftsmanship?..

 

[72bluNblu]

These , should be interesting... How was the AFCO quality ,& did you like the craftsmanship?..

The AFCO's are great, the roller bearings are nice and smooth and everything is well built. I was really happy with the quality. And they offer replacement parts, should you want to change your roller bearings etc. I've also been really happy with the AFCO springs, not nearly as much sag as the Mopar XHD's I put on my Challenger. Only beef with those is they came plain, and I should have painted them before I installed them. But really that's my fault, I obviously realized they weren't painted.

The Calvert sliders look to be just as good though, and they have the angle built in. Now, it's a generic angle, so it won't be perfect either, but it would be closer than the AFCO's mounted flat. Somewhere I'm sure there's an equation for that angle based on the spring length and the relative mounting height of the front and rear spring eyes.

 

[fez440]

nice write up. thanks for the info

 

[72bluNblu]

nice write up. thanks for the info

No problem. That's how I understand it anyway. The sliders are nice, but they probably fit into the category of "cool things I did that I don't really notice when driving". They definitely go with the theme of optimizing how my car functions, but realistically they probably won't make my car faster.

Oh, another benefit of the sliders- they allow less lateral movement of the springs. Shackles have bushings, and because of the give in the bushings the springs can move side to side when the shackles put load on the bushings. The shackles, being several inches long, also magnify this effect because the shackle acts like a lever arm between the spring eye and upper pivot. Because the pivot and spring eye are in the same place on the slider, there's no lever arm, and the bearings and spacers don't allow as much lateral movement as the shackle bushings do. All of which help reduce the side to side movement of the rear axle, which is important if you've jammed really big tires into a space that they barely fit in. Like my 295's in the stock wheel tubs. ;-)

 

[fez440]

No problem. That's how I understand it anyway. The sliders are nice, but they probably fit into the category of "cool things I did that I don't really notice when driving". They definitely go with the theme of optimizing how my car functions, but realistically they probably won't make my car faster.

Oh, another benefit of the sliders- they allow less lateral movement of the springs. Shackles have bushings, and because of the give in the bushings the springs can move side to side when the shackles put load on the bushings. The shackles, being several inches long, also magnify this effect because the shackle acts like a lever arm between the spring eye and upper pivot. Because the pivot and spring eye are in the same place on the slider, there's no lever arm, and the bearings and spacers don't allow as much lateral movement as the shackle bushings do. All of which help reduce the side to side movement of the rear axle, which is important if you've jammed really big tires into a space that they barely fit in. Like my 295's in the stock wheel tubs. ;-)

thats what i was thinking. i think when fitting a big tire and your tolerances are so close whatever you can do to limit side movement is a benefit

 

[72bluNblu]

moparmat2000 asked me for a template for my slider brackets. I didn't make a template when I made them, but here's a better write up, as well as dimensions, for the slider brackets I made. You could use these to replace the shackles in either the stock location or with a 1/2" offset (mine are offset a 1/2").

So, to make the upper part of the bracket I used 3"x3"x.125" square tube and cut it off at an angle. The pieces I used weren't quite cut at 45*'s, the tall section is 3.25" and the leg is 3". The bottom plate I used was 3"x4"x.25", so the overall height of the brackets ends up being 3.5" once the bottom plate is welded on. If I had to do it again, I would make the lower plate 4.25" long, because as you can see in the picture I ran a little short. By the same token, the lower leg of the bracket can be longer, doesn't hurt anything and it would make the bracket stronger. The height should stay ~3.5", because otherwise the bracket won't fit. It doesn't have to be perfect as long as the bottom plate sits flush with the frame extension, but it has to be close because the bolt pattern doesn't leave much clearance for the bottom bolt. I used the old shackle hangers to set the bolt pattern, just make sure you use both the L and R hangers for the pattern because they are different side to side (mirrored).

Here's the dimensioned picture. It looks a little wonky because of the angle of the picture, but the dimensions are correct.

 

[DaleC]

Finally, let's get them on the car. In the back, in addition to my 1/2" spring offset, I took another 1/4" off of the quarter lip.

The front was a little more complicated. I added a set of Magnumforce tubular UCA's, which I had bought for the car awhile back and hadn't got around to. I also installed a 13" Cobra brake kit, courtesy of Dr. Diff. That added 3/16" to the track width, which worked with the 18x9's and 35mm offset. The center bores of the enkei's started at 73.1mm like a lot of rims, but necked down to 66mm, still not enough to clear the hubs. So I had my machinist open them up to clear the hubs.

While I was at it, I installed a new set of Hotchkis Fox shocks I picked up from another forum. Not the fancy new adjustable ones, but good enough for me. I also upgraded to FFI's 11/16" solid adjuster tie rods.

They do look nice...

Still working ride height a bit, and the alignment is just roughed, but here she is for now...

So the almost final verdict? The fit. No rubbing so far, but it is definitely close. About a 1/4” to the springs in the back, and no more than that to the cut down quarter lips. I don’t think I could go much lower in the back without re-working the inner fender well a little, there’s a “bump” that narrows the well not very far up.

Anyway, final specs-

Front: 275/35/18 on an 18x9” rim with 35mm offset (6.4” backspace). Dr. Diff 13” brake kit, so effective offset 30mm, effective backspace 6.2”

Rear: 295/35/18 on an 18x10” rim, 38mm offset (7” backspace). 68-70 B body 8 3/4 (54 15/16” flange to flange) with 1/2” spring offset and 1/4” lip trim

Great looking car! I love the stance and these wheels!

 

[813Demon340]

Great thread, I read through it and really like you you've done. You provided many ideas for my Demon build, so thank you! Any new updates on the Duster/ Demon..Dustdevil maybe?

 

[72bluNblu]

Great thread, I read through it and really like you you've done. You provided many ideas for my Demon build, so thank you! Any new updates on the Duster/ Demon..Dustdevil maybe?

Thanks! :thumbup:

Dustdevil! That's pretty funny. I may have to use that. No, nothing major in the update department. I've been driving the car too much lately, been working on the brakes on my Challenger because the m/c went out and working on my '71 F100 because I let it sit too long.

I've just been collecting parts for the Duster for it's next series of updates. I've got a set of Bergman AutoCraft SPC adjustable UCA's and QA1 tubular LCA's ready to go on, and I bought all the parts/tools I needed to really do all my own alignments (turntables, camber/caster gauge, toe plates, etc). I've been waiting on US Cartool to come out with their T56 crossmember, the plan is to drop the K, make the mods for a T56 swap, and put the new LCA's on when everything goes back together. Probably paint the engine compartment while I'm at it. So I have to get my other vehicles back to daily status so the Duster can get worked on for a bit. But if everything works out well it will go back on the road with a T56 in place, and hopefully that will be the last big mechanical change for a bit.

 

[dusterbd13]

this is a great thread. thank you.

I may steal the rally dash mod for mine, and will definitely be copying the spring sliders, afco leaves, etc.

and I love the rfp1 wheels. hadn't seen them on an a-body, but then again, ive never seen a car they DONT look good on.

im now subscribed, and will be a lurker.

 

[dusterbd13]

Now, for the finished product and my "trick". Not really a trick, I originally purchased a carbon fiber overlay from Detroit Muscle Technologies on eBay. I was darned impressed with the product, so I contacted the owner, Jim Fillmore, about making lower overlay pieces as well. After mailing back and forth a few rally dashes, Jim sent me back a set of lower carbon fiber overlays. rayer:

Unfortunately, because the dash for my Duster isn't stock, I had to do a little trimming of my own. But it all worked out! I did a ton of buffing on the painted sections of the dash, which now are pretty much a gloss black. You can see the reflection of the gauges in the upper part of the dash. I also glued the lenses and everything back into the dash.

The lower overlays are just laid in. As you can see the holes for mounting the dash are covered, so final installation of the overlays has to be done in the car with the dash mounted already, unless you want to cut out the holes (a single hole paper punch would work great!). I opted for the clean look.

And before anyone asks, here's a link to the carbon fiber overlay and the DMT website. The overlays aren't listed on the site, just eBay.

Carbon fiber overlay

The ebay store

Items in Detroit Muscle Technologies LLC store on eBay!

And the DMT home website.

DMT Detroit Muscle Technologies Gaskets AMC Mopar Dodge Plymouth Chrysler Ford Mercury GM Chevy Pontiac Chevrolet

Keep in mind these overlays are also made in the original woodgrain. The lowers aren't listed for sale on eBay yet, but I'm guessing if you contacted Jim through his website he'd be able to help. The lowers should be available in a semi gloss black and a silver color, to match the original layouts.

I just got the barracuda glovebox piece to use. is this the plast-aid you used?
Amazon product ASIN B00B2QUNGM

 

[72bluNblu]

I just got the barracuda glovebox piece to use. is this the plast-aid you used?
Amazon product ASIN B00B2QUNGM

Yup, that's the stuff. Make sure you're in a well ventilated area.

 

[dusterbd13]

Where's the fun in that???

Will do. I'm assuming it's some pretty nasty stuff.

 

[72bluNblu]

Where's the fun in that???

Will do. I'm assuming it's some pretty nasty stuff.

It's like super glue fumes x1000.

 

[PlumCrazyChris]

Love the build, really cool stuff. Any updates to your car? Did you get it all black yet?

 

[72bluNblu]

Not a whole lot in the update department for the Duster, just a few odds and ends. I filled the area in the rear support where the shock bumpers were mounted and made the corner fill pieces to cover the gap between the tail panel and the bumper, completing the work I did earlier to hang the earlier '71 bumper on it. The tail and support panels now more closely match the earlier style. And I finally leaded the seam where the the tail panel attaches. So there is some new black paint but it's just rattle can over the leaded corners.

I've mostly been working on my '71 EL5 GT, trying to get it back together so I can shuffle my projects around. My Challenger is torn down and needs some extensive metal work so I wanted to finish all the welding on the GT before I swap spots with the Challenger. I added a full US Cartool stiffening kit to the GT and need to button up the interior, plus finish the transmission rebuild to I can put the driveline back in. So the Duster is doing daily driver duty and remains black and tan.

 

[75slant6]

You have a build thread on your dart and challenger?

 

[72bluNblu]

Not really. I have a thread for my Dart that hasn't been updated since a few months after I got it, so, years ago. And nothing for the challenger. I have pictures of most of my work on both just for reference. I suppose I should update the one for my Dart at least. Although if I posted all the stuff I did to all of my cars I would probably spend more time posting than working.

 

[72bluNblu]

Ok, it's about time I did something to my Duster, so here's the update. I've been sitting on a set of TTI shorty headers, SPC upper control arms and QA1 lower control arms for awhile now. Like years apparently. I finally got some time, so I figured, what the heck. Pull the Doug's 453's, gain some ground clearance, install the SPC's and QA1's, lower the car a smidge and pick up some more suspension travel. Heckuva plan.

So first, I "fixed" the brand new QA1 LCA's. I had a set of these, made by CAP before they sold the design to QA1, on my Challenger. One of the welds failed. Now, QA1 welding is way better than CAP welding, but given what that failure taught me about the LCA's, I decided to add some gussets.

Brand new and powdercoated QA1 goodness

There's a seam right here. That's where my CAP built arms failed, the weld separated.

Like this- the old arm built by CAP from my challenger. The QA1's wouldn't do this, look how lousy those welds are on this CAP piece. The QA1 built pieces are so much better.

But, gussets added to the top and bottom. Don't worry, they clear the torsion bar lever.

Not sure why these come with rubber LCA bushings. Brand new tubular arms with rubber bushings! So, out with those, in with Delrin bushings from Peter Bergman.

bushing and LCA pins out

Shells out

Delrin in

 

[72bluNblu]

Fun stuff. So here's what we started with. Magnumforce non-adjustable tubular UCA's, stock gusseted LCA's, modified short lower bumpstops and cut down bumpstop plate, taller upper bumpstop.

Then things got fun. I dropped the adjustable strut rods off the LCA's, pulled the shocks, undid the sway bar and used the LCA to push the torsion bars out. The LCA's had poly bushings, so, the LCA pins stayed in place and the LCA's slid right back.

For those that want to know, like 12k miles on the poly bushings and they're fine. Like brand new still. Not "hammered out of shape" like I've heard before. Anyway, the Delrin bushings were a great fit to the Firm Feel greaseable LCA pins. Like perfect. Per Peter I cleaned off all the grease, because the Delrin doesn't need it. But I kept the pins. I'm leaving the headers out of this for now. I installed the QA1 LCA's on the pins, and made a big mistake. Always clean all the powdercoating off of the torsion bar ends and sockets. Firm Feel powdercoats their hex ends on their torsion bars, and QA1 powdercoats their sockets. It makes life miserable trying to install the torsion bars. So I removed the bars and LCA's, scraped off powdercoating, and re-installed. Much easier.

And by this time I was really working, so, pictures went away. The QA1 LCA's don't have the sway bar mounts as high on the arm. Result- you need shorter end links or your 73+ Hellwig sway bar bottoms out in the K member. Fortunately, I had some shorter sleeves and bolts to make this work. Also, the QA1 LCA's don't have bump stops. This is a part of why I measured an extra inch of travel on the QA1 LCA compared to my stock LCA's with shorter bump stops. Compressed shock distance on the my old LCA's was ~10.5". On the QA1's it was ~9.5 if you went metal to metal. But, that would also result in the tire hitting the top of the inner fender. So, I added some bumpstops.

These are just the same ones from my old LCA's. .375" tall poly bumpstops. I drilled the frame stop for them and viola.

Then I installed the QA1 LCA's and readjusted my strut rods to match them. It was pretty close to the same, but some small adjustments were needed to keep everything bind free. I checked the range of motion bumpstop to bumpstop. Which, if you're curious, was about 6" of travel on my car measured from the lower ball joint. With the bumpstop in place it was 13" from the spindle to the inner fender centered over the tire. So, my 25.7" tall 275/35/18's shouldn't touch it. Hopefully.

The UCA's were the easiest part of the deal, just removed the old ones and installed the new SPC adjustable ones, also from Bergman Autocraft. But one surprise- I figured out how I got 8* of caster. The old magnumforce UCA's had Moog offset bushings. So, like +3* from the UCA's, and another +2* from the bushings, that's how I got +8* maxed out. Oops. I can't remember if I installed the bushings anymore or not, I know I bought the magnumforce UCA's used. That's why I should write everything down.

And here's everything- SPC adjustable UCA's, Howe racing ball joints, new proforged lower ball joints (because why not), shorter endlinks (by like 2"!), QA1 tubular LCA's, and a fancy bumpstop. Which stole like a 1/2" of travel from the arms, BTW. But it beats bottoming the tires on the inner fenders. The new QA1 tubular lowers have apparently been redesigned with a bump stop now, so, no change in travel for the new ones.

So, this is the final installed picture, who sees it?