91-92 Buick Roadmaster rearend

I have a line on a 91-92 rearend w/sway bar. Out of a Buick Roadmaster. The price is good.

I believe it also has 11"brakes. I think this will fit under my 79 Caprice!?!

It should have at least 3.42 or 3.73 gears. I will know more tomorrow after they pull the cover.

Any advice on this rearend! I will measure it for length etc. I believe its
an 8.5.

Otherwise it would have the smaller brakes.


Any thoughts????

P.S. Corrected from the ad.

The 91+ gm B body rear axle will bolt up, but there are two things to keep in mind:

1) the bolt pattern on all 91+ b bodies was 5 x 5" bolt circle. The 90 and below came standard with the 5 x 4.75" bolt circle except for police package and station wagons.

2) the rear axle was slightly wider from flange to flange. I don't think it's enough to cause your tires to rub the fender or anything, but just wanted to make you aware.

I called today and they have pulled the cover. They have stated its a posi. 3.08. ( already have highway gear--2.56)

I will go look at it Monday and check the numbers. Its an 8.5 for sure. Comes with upper and lower arms and a sway bar.

We shall see.

I have already done this swap in my 79 Impala and it was easy easy no issues at all. Other than the 5x5 bolt pattern

it's a drop in swap. I would recommend redoing the Drums before the swap mine were a mess and it was lot easier to do

them off the car and the cost is silly cheap like 30 for the rebuild kits and the shoes maybe another 15 if you wanted to

do the brake cylinders. The ebrake might take a little cobbing but it only took me an extra 20 min to get it going. The

whole swap including the e brake was done by me and neighbor with mostly hand tools in 3 hours or little less. Definitely

worth it the 7.5s from the 70s are crap, very weak and easy to break with any kind of power. The difference in weight

was at least 30lbs between the 7.5 and 8.5

I should also point out with a fresh brass block for the brake tie it's a snap as well. My original block that sits above the rear

on mine was stripped but with a 2.79 replacement I was able to hook up the Impala brake line with the rearend in few

minutes a quick bleed and I have had absolutely no issues since. You maybe lucky and your block is good still and you won't

even have to spend 2.79! Also people may knock the drums but honestly my car stops on the dime and has way better

stopping power than I'd originally thought it would. Of course a B Body 2 door is a much lighter car than the B bodies this

rear came with the 91-96s are heavy in comparison.

I got the rearend home. I check it before leaving the yard, its 3.08.

Yesterday I went to work tearing it down. I had the uppers and lowers (what was left)on. Plus the sway bar.

The sway bar is already at the cleaning and powder coating company.

I had a heck of a time pulling the drums. One was easy the other, not so.

I will take it all the way down and clean and inspect it.

Most likely new drums, brake hardware including brake cylinders.

I may have the whole rearend powder coated. It looked good on the G-Body I did in past.

Now to knock out the upper bushings. Fun time.

Are the studs 1/2 thread as well, or metric?

More later.