Stacking aluminum lowering block?

[72bluNblu]

I already have questions about the pinion angle, but that's another story. It has a 65/67 B body 8.75 that has the perches moved to 43" on center to fit which checks out but the pinion seems angled up a little excessively.

A and B bodies used different spring perch angles. If you kept the angle the same when you moved the perches you'll probably need to shim them to get the right angle. And a 2" lift spring will also change the pinion angle quite a bit.

With a 65-67 B-body rear you're going to need about 5.75" of backspace to clear 275's on a 15x8 if you put the car at stock ride height.

 

[Mojoe9955]

Well if they're 2" lift springs that would certainly explain the arch and why the car sits so high in the back. The best way to deal with that would be to have them de-arched



Which B-body rear axle do you have?

Cop wheels are 15x7 with a 4.25" backspace. With any B-body rear that still won't be enough to clear 255's on those rims with you lower the car, let alone 275's.

I have a 68-70 B-body rear axle in my Duster, and even at stock ride height the most that would fit on cop wheels was a 225/60/15, and they were very close to rubbing. The 68-70 B rear is 60 1/8" wide, even if you have the shorter 65-67 rear that's still 59.5" wide, so you'd only gain 5/16" in clearance per side, which probably wouldn't even get you to a 235 unless the quarter lip is well above the tire, like it is now. To clear 275's on a stock height or slightly lowered car you'd need a lot more backspace.

I'm driving it around with the 275's now and they rub a bit on bigger bumps. It seems fine with the 255's but as you say, I might not get them "tucked in".
I have an A body 8.75, 489 case with a 4:10 Sure Grip but no axels. I have 3.55 gears now which are fun...you know how it goes

 

[Mojoe9955]

I'm driving it around with the 275's now and they rub a bit on bigger bumps. It seems fine with the 255's but as you say, I might not get them "tucked in".
I have an A body 8.75, 489 case with a 4:10 Sure Grip but no axels. I have 3.55 gears now which are fun...you know how it goes

The rear came with the car soon as I looked at it I knew something was wrong. Not to mention the springs were shot, no bushings, missing binders. I got a good deal on the springs from a local guy who was cleaning house.

 

[Mojoe9955]

A and B bodies used different spring perch angles. If you kept the angle the same when you moved the perches you'll probably need to shim them to get the right angle. And a 2" lift spring will also change the pinion angle quite a bit.

With a 65-67 B-body rear you're going to need about 5.75" of backspace to clear 275's on a 15x8 if you put the car at stock ride height.

The rear came with the car soon as I looked at it I knew something was wrong. Not to mention the springs were shot, no bushings, missing binders. I got a good deal on the springs from a local guy who was cleaning house.

While driving I was thinking about swapping out the 17" Bullet wheels from my 70 Duster with 8.25 to the 74 and put the 255 cop wheels combo from the 74 to the 70...

 

[72bluNblu]

While driving I was thinking about swapping out the 17" Bullet wheels from my 70 Duster with 8.25 to the 74 and put the 255 cop wheels combo from the 74 to the 70...

The backspacing on the Bullit's would be pretty good for the 65-67 B body rear axle. And the cop wheels would be a better match for the 8.25, although with a 255 they'll be real close to the springs without a small spacer

 

[Mojoe9955]

The backspacing on the Bullit's would be pretty good for the 65-67 B body rear axle. And the cop wheels would be a better match for the 8.25, although with a 255 they'll be real close to the springs without a small spacer

I'm going to try it, thanks. If they'll work, I think I have some 1/4 spacers somewhere. If not there is always eBay or Amazon.
Thanks again

 

[72bluNblu]

I'm going to try it, thanks. If they'll work, I think I have some 1/4 spacers somewhere. If not there is always eBay or Amazon.
Thanks again

Hey you've got both cars and all the wheels, so you might as well try it right?

If nothing else it will give you a much better idea of what kind of backspace you need on each car to maximize your tire sizing if you decide to buy a new set of wheels. But I think the switch will fit both cars better than their current wheels.

 

[lead69]

If you do a google search you will see guys who run 7s/8s in the qtr. on leaf springs with steel lowering blocks, a couple had blocks as much as 4". Opinions are kind of like the whole wheel spacer thing and you will see those guys running them as well at those times. I used these
LOWERING BLOCKS/pair (LB-01) – Calvert Racing, Inc.
as they can be stacked and are really good quality. I talked with calvert racing and ended up lowering mine 2" overall (my blocks are welded together) I have caltrac mono leafs and bars and have zero issues.

 

[Mojoe9955]

I'm looking at an A body 8.75, with 5x4.5 Strange axels with 3" studs, backing plates, brake shoes and hardware. It comes with springs but no chunk. The seller wants 1k. Knowing what I know now...which really isn't much and having a 68/70 B body 8.75 and stock A body 8.75, both of which are missing the axels and brake parts. I have a 489 case with 4:10 Sure Grip, which I might swap to 3.55 which I like in my 4 speed car, but not so much in the auto. I'm also thinking of some 3.23 also. This is for a 72 slant 6/904 Demon that needs and overhaul.
I'm liking the idea of rebuilding that setup with some more power and some trick slant 6 stuff.
I'm liking the enki wheels that Blu is running on his rig. This all being said,
Which give more bang for the buck?
Thanks

 

[Mojoe9955]

I'm thinking about offering $500, but considering everything I need excluding the brakes is about $750 regardless of what I build from Doctor Diff, am I better of to do that?