1972 cutlass s with 350 stock car what rear end would I have.

 

If its the factory one it would be the corportate 8.5" ten bolt. Probably a non-posi with highway gears, 2.56, 2.78 or 3.08's. But you've got a desirable rear end for building if you want to change gears and add a posi. Read through some of the posts by Monzaz and 507OLDS discussing various rear ends. Yours has the best selection for parts and interchange from many different GM cars of the 1970's and I believe going into the 1980's. John

 

You can also post pictures of the rear cover JUST to be sure someone has not swaped out the rear over 40+ years.

10 bolt 8.5 was used from 1970-1999 and renamed 8.5 from 1998 -2011 THe carrier bearings were increased in diameter BUT the ring gears from 1970-2011 are all interchangeable. Jim

 

Rearend

 

That is a 10 bolt 8.5 rear diff. I call them the BUICK 8.5 10 bolt because of the rear cover . The olds 10 bolt 8.5 usually has the round rear cover with half a oil trough. (reference picture)
Either way We have seen them under BOTH.
I would assume it is original If you have the axle tube suffix 2 letter code we could know for sure.

Jim

 

Here is my factory 8.5" 10-bolt rear end off my '72 Supreme...

 

Where can I find the code, is this any different because I'm about to get it rebuilt.

 

Will the W 27 cover fit this rear end?

 

this kind?

 

YOU have a 8.5 10 bolt ALL 8.5 covers will fit the rear. So YES that cover as long as it has 10 bolt covers and is for 8.5 will fit your rear diff housing. NO WORRIES.... Jim

 

This is a 8.5 for sure or do I have to pull the cover to be exact because I need to order parts for it.

 

That IS an 8.5" 10-bolt.That style came under all of the 71-72 Buick Skylark/GS cars,and it came under the 71-72 Cutlass/442 cars that were not built in Lansing Michigan.All of the Lansing-built 71-72 Cutlass/442's that I have seen,had the other style cover,like Monzaz & Oldzy posted a picture of.
The style with the notched cover,like yours,has a large "A" cast on the top of it,and on the sides,facing the front.The style with the round cover has an "O" cast on each side of the pumpkin,facing the front. BOTH are 8.5's,and BOTH takes the same parts.The W27 cover will fit both of them.

 

Makes sense mine was made in California. I'm going to get it rebuilt in the states and do posi with 3.42 gears.

 

Before I get my parts the guy wants to know if it is the bop style with bolt in axles? How many ring gear bolts hold the carrier? axles spline and gear and pinion gear?

Also this is the kit I am getting, any opinions on this stuff.

http://cgi.ebay.com/ebaymotors/GM-8-...ht_2766wt_1165

 

Sounds like this guy is NOT to knowledgeable on the older rears...God help you....lol. Jim

IT IS A 8.5, ALL 8.5 rears use the same ring and pinion and parts in the center section area.

It is bolt in axles....ALL 1971 1972 8.5 A-bodys are. This will not make any difference on the rebuild kit he needs.

Axle bearings are A9 and seals are 712146.... MAKE certain he gets the correct SEAL or you are DOOMED! NOT THE 2146 MUST BE 712146

Good Luck! AND may the FORCE BE WITH YOU LUKE!!!

 

Do you build 8.5 10 bolt rear ends and do you have a website?

 

Jim, I had no idea the 10 bolt was used to 2011! I assume these must have been used in trucks? Which ones?