72CUTTY

I have a 72 Cutlass. Need info on this rear end. 8.2 or 8.5? Planning on putting a posi on it soon but my local shop charges me 1300. I think if i can figure out what i need and what i have, i can probably get it done cheaper. Any help would be appreciated!

Allan R

Monzaz = Jim Mitschke
J D Race & Restoration
Muscle Car Differential Specialists
Richfield, Oh

507OLDS
Brian Trick
Erie,PA
thetrickfamily@yahoo.com
814-440-3553

Both of them are specialists with rear suspensions and drives.

monzaz

1971 1972 Cutlass 8.5 10 bolt rear - Bolt in axles
A9 axle bearings with 712146 seals
28 spline axle shafts
SA 2.73 ratio NON POSI standard open rear one wheel peel.


Hope this helps. Jim

I have parts if you need a quote...Might save you some money on parts anyway. Jim

JD

72CUTTY

Thanks alot jim!

72CUTTY

what do you guys think?


http://www.ebay.com/itm/GM-8-5-3-73-...4#ht_727wt_649

72CUTTY

just bought it! see how it goes!

Rickman48

Ain't gonna go too good - those tires reduce the rear ratio to about 2:25 to 1!
Good luck with it!

72CUTTY

lol.. I since then took those rims off. Bought me some oldsmobile 14 inch and beauty rings.

72CUTTY

I need help guys! So i ordered the package above from ebay. I messaged the guy and told him they were for a 72 cutlass with 8.5 rear end. He messages me back and ask me if im sure its an 8.5 and not an 8.2. So i tell him im sure its an 8.5 and gave him this info

1972 Cutlass 8.5 10 bolt rear - Bolt in axles A9 axle bearings with 712146 seals 28 spline axle shafts

Then he replies with this...

This is the correct package as long as you are 100% sure it is an 8.5. The pinion should have 30 splines. Thanks..

What do you guys think? Is it going to fit?

Allan R

Not sure why you bought it first without checking with Brian or Jim....
I bought my posi from Jim. I have a 72 8.5 corporate 10 bolt. Axle splines are 28, pinion is 30, gears are 3:23

So yours should fit.

Troys Toy 70

Hey Allen..... Are you happy with the 3:23's, what did you have before?

Allan R

Well, sort of. I just got the carrier from Jim last July. Since then I've been more focused on doing the front end rebuild, so the rear axle still has to come out. I'm not going to do the install myself - I'll farm it out to a local rear end shop I trust. They can install and shim it properly way quicker than it will take me. The old rear is an open 2:73
Looking for this to be done in the summer.

I'm going to be very happy with the 3:23's whether I like them or not! FWIW I did think about 3:08s and 3:42s. For what I want do do with the car though 3:23's are the answer. I'll use more gas, but so what? It's not like this is a daily driver. If it was I'd just keep the 2:73s on the posi.

Troys Toy 70

Well at least you're happy. I just parted out my 72, which I put a Chevy 12 bolt in with 3:73 which I pieced together back in the day. It was way to much for what I want today. Really debating between the 3:08's or 3:23's as a final ratio. Whether I use that rear end, or put a posi in the one in the car, it is at least a 12 bolt cover. I'll admit thought I still confused about the 8.2 and 8.5 inch and whether its an O rear end or corp. I need to take some pictures and send to the rear end guys. So I know what my options are.