Identify this 8 3/4

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gunters96lt1

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Guys, I picked up this 8 3/4 for my duster. It measured out to fit perfect, only I wasn't paying attention and the spring perches are on top of the axle tubes. It has a 489 case. Anyone know what this might of came out of?

 
Truck or van, A100 or A108. I used to have one in a 72 Duster.
 
IIRC Those axles are likely the thick, non-tapered shafts that can be shortened and re-splined..

Someone was searching all the C - Body 's for this style axle.. jmo

cheers
 
Awesome thanks for the info guys... Worth it to cut the perch's off and reweld under or look for another 8 3/4?
 
I would just get new perches and re weld them. You can buy them for like 20 bucks. Then weld them and your done.
 
70's D100 truck. Over all length is too long. I'd get it shortened, perches on the bottom, and axles too if not tapered. Have it done to 68 Hemi Super Stock dimensions. Axles to 27 13/16, to keep 4 1/2 inch BC to use standard offset BBP wheels. Housing to match. Hopefully it has 3.55 gears. Moser knows what they are doing.
 
Tag says 3.23 but its open center but I can get a posi from the guy I got the rearend from.
 
What is the width?

I would say it's a truck rear end, which would make it a tough fit even in a duster without cutting it down. Even the A100 axles were 61 3/4", which is still quite a bit wider than the 68-70 B-body 8 3/4 I'm running in my Duster. It's 60 1/8", and I use rims with a 38mm offset already.
 
I don't know how it "measured out perfect" that thing is way to wide to fit a a body with out looking "donk style" Best thing to do is have it narrowed to a body width, send moser the axles and get them shortend and reslpined to a body width, and be done. Not very expensive either really.
 
replicaracer43 said:
Best thing to do is have it narrowed to a body width, send moser the axles and get them shortend and reslpined to a body width, and be done. Not very expensive either really.
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Not for a Duster. I wouldn't go anywhere near A-body length for a Duster with stock or even 1/2" offset springs.

If you want to be able to rotate your tires, and you don't want the rear end to look narrower than the front, your best bet is to narrow it to 65-67 B-body specs, or 54 1/4" flange to flange. That will match the wheel offsets front to back pretty closely.

You could go with a custom width too, but the 65-67 B rear is so close to where I would want it to be for a Duster with the stock spring locations I wouldn't mess with it. That way if you ever wanted to buy aftermarket axles you could just buy them off the shelf instead of having to pay extra for a custom length.

When I switched out my 7.25 for an 8 3/4 on my '74 Duster I used a 68-70 B-body 8 3/4 rear. It's wider than the 65-67 by about 3/4", but I was still able to run 15x7" police rims with a 4.25" backspace and 225/60/15's all the way around. I was too close to the quarters to run anything wider than that, but the 65-67 rear would solve that, it wasn't much. Kind of moot anyway as it's pretty hard to run anything wider than a 235 on the front with 15" rims. And if you go to larger rims, say, 17 or 18, you'll find that the offsets needed front to back will be VERY similar, with ideal for max tire width being about a 25mm offset front and back.
 
72bluNblu said:
Not for a Duster. I wouldn't go anywhere near A-body length for a Duster with stock or even 1/2" offset springs.

If you want to be able to rotate your tires, and you don't want the rear end to look narrower than the front, your best bet is to narrow it to 65-67 B-body specs, or 54 1/4" flange to flange. That will match the wheel offsets front to back pretty closely.

You could go with a custom width too, but the 65-67 B rear is so close to where I would want it to be for a Duster with the stock spring locations I wouldn't mess with it. That way if you ever wanted to buy aftermarket axles you could just buy them off the shelf instead of having to pay extra for a custom length.

When I switched out my 7.25 for an 8 3/4 on my '74 Duster I used a 68-70 B-body 8 3/4 rear. It's wider than the 65-67 by about 3/4", but I was still able to run 15x7" police rims with a 4.25" backspace and 225/60/15's all the way around. I was too close to the quarters to run anything wider than that, but the 65-67 rear would solve that, it wasn't much. Kind of moot anyway as it's pretty hard to run anything wider than a 235 on the front with 15" rims. And if you go to larger rims, say, 17 or 18, you'll find that the offsets needed front to back will be VERY similar, with ideal for max tire width being about a 25mm offset front and back.
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Cant disagree with what your saying, but I don't personally run the same size tires front and rear, my cars are more old-school with skinnier tires in the front than the rear. In my opinion, part of what makes a duster look tough, is having some dish in the rear.... Now......if we are talking autocrossing and performance handling, then that's a different story!
 
replicaracer43 said:
I don't know how it "measured out perfect" that thing is way to wide to fit a a body with out looking "donk style" Best thing to do is have it narrowed to a body width, send moser the axles and get them shortend and reslpined to a body width, and be done. Not very expensive either really.
Click to expand...

Me? Perfect all around gears. I already said it was too long, and suggested that it be shortened.
 
replicaracer43 said:
I don't know how it "measured out perfect" that thing is way to wide to fit a a body with out looking "donk style" Best thing to do is have it narrowed to a body width, send moser the axles and get them shortend and reslpined to a body width, and be done. Not very expensive either really.
Click to expand...

I meant spring perch to perch measured (cant remember exact number) as the bigblockdart.com info gives.

Relax, Im not shooting for "donk style" I was just simply asking if anyone thought I can make this work or just be easier to find another rearend.
 
gunters96lt1 said:
I meant spring perch to perch measured (cant remember exact number) as the bigblockdart.com info gives.

Relax, Im not shooting for "donk style" I was just simply asking if anyone thought I can make this work or just be easier to find another rearend.
Click to expand...

No problem, we are all just trying to help......
 
gunters96lt1 said:
I meant spring perch to perch measured (cant remember exact number) as the bigblockdart.com info gives.

Relax, Im not shooting for "donk style" I was just simply asking if anyone thought I can make this work or just be easier to find another rearend.
Click to expand...

Spring perches are easy to move. And since those perches are on top of the axle instead of the bottom, you'd have to do that anyway.

The width of the rear axle is more important, and harder to change. That said, you already have that rear axle, and having it narrowed would be cheaper than buying an A-body 8 3/4. Even the B body axles have gotten more expensive.
 
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