Gears & Axles - GM 8.5" 10 bolt width?!?!

Alright so i need to know how wide the 10 bolt 8.5" under an 85 1/2 ton c10 is. I'm also wondering if i can swap it for an 02 camaro rear end if it's more narrow for wider tires. I know the bolt patter is different but I don't really care :D

I don't know if that would even work, the suspension design is totally different. You'd have a lot of custom fabbing to do to make it even bolt in, in which case the width would be the least of your worries I would think.

I'm no pro but I considered an 8.5/8.6 10 bolt as possible upgrade option, but given how much work it would take to get it to even bolt into the car makes me think it isn't even worth bothering with over the other readily available and proven options.

I don't know if that would even work, the suspension design is totally different. You'd have a lot of custom fabbing to do to make it even bolt in, in which case the width would be the least of your worries I would think.

I'm no pro but I considered an 8.5/8.6 10 bolt as possible upgrade option, but given how much work it would take to get it to even bolt into the car makes me think it isn't even worth bothering with over the other readily available and proven options.

Well I planned on doing a triangulated 4 link with coil overs inside the frame rails :) So I'm redoing the suspension entirely

Oh, well, if you're totally redesigning the whole thing then :D

I just don't know how much power the 8.5" 10 bolt can hold in comparison to others. I know it has some strength to it compared to the wimpy 7.5" that these cars came with, but then almost anything has more strength so that isn't necessarily saying much :shiner:

Oh, well, if you're totally redesigning the whole thing then :D

I just don't know how much power the 8.5" 10 bolt can hold in comparison to others. I know it has some strength to it compared to the wimpy 7.5" that these cars came with, but then almost anything has more strength so that isn't necessarily saying much :shiner:

Put many 6.0 passes on a 8.5" 10 bolt with 4.88 gears, mini-spool and stock 28 spline axles, leaving off transbrake. One axle finally broke after several 5.9x passes behind the 572 so they are pretty tough, especially if you put a spool and axles in them.

GM really should have used an 8.5/8.6 center section in these cars to begin with. Does the 7.5" even exist in any other vehicle?

GM really should have used an 8.5/8.6 center section in these cars to begin with. Does the 7.5" even exist in any other vehicle?

That's one of the mysteries of the universe, considering that the 8.5 stayed in production long after GM stopped using it in F-bodies. Impalas and similar cars had them until 1996. Trucks... Dunno. I'm sure the 7.5 had to do with cost, weight and or CAFE standards. My experience with the 8.5 has been universally good. The most recent "death" by my hand came as a result of age (100k miles), and abuse (low oil, poorly fixed seal). None of the hard parts actually broke, and everything was either fine or easily replaced with relatively cheap and stronger parts.

My car doesn't have crazy horsepower (@380), but it will very high speeds and hard braking for extended periods. I don't feel compelled to go with a mega buck conversion.

Buick gn cars and hurst olds of the 80's came factory with a 8.5 10 bolt. Maybe an easier swap

my buddies 71 bird has a 8.5

my buddies 71 bird has a 8.5

Yup. F-bodies had them until 1981.

if you want the 8.5. just get one, have it narrowed and put c-clip elims/ford bearing caps on it and new axles with the right pattern installed.

Thats how to make the 8.5 a beefcake.

but for 700 you can order a 9inch with custom axles at a custom length from Quick performance.

Then just choose your 3rd member.

After i broke my 12bolt for the 5th time i upgraded

if you want the 8.5. just get one, have it narrowed and put c-clip elims/ford bearing caps on it and new axles with the right pattern installed.

Thats how to make the 8.5 a beefcake.


Funny you should mention that. I just posted mine for sale in the classifieds section (http://ls1tech.com/forums/parts-classifieds/1579383-2nd-gen-10-bolt-moser-axles-new-gm-diff.html#post16668603) here.

if you want the 8.5. just get one, have it narrowed and put c-clip elims/ford bearing caps on it and new axles with the right pattern installed.

Thats how to make the 8.5 a beefcake.

but for 700 you can order a 9inch with custom axles at a custom length from Quick performance.

Then just choose your 3rd member.

After i broke my 12bolt for the 5th time i upgraded

How does the torque arm etc mount with this unit? Do you have any photos you can post up?

How does the torque arm etc mount with this unit? Do you have any photos you can post up?

The 8.5 inch 10-bolt was never factory-supplied on third or forth gen F-bodies, just the earlier cars, which had leaf spring suspensions and also didn't use a torque arm. Sorry. I've seen some traffic on other sites where putting a torque arm on a 90's B-Body/Impala SS 10-bolt (which is an 8.5") was being done, but I don't know how big of a pain it would be to stick one of them in an F-Body.