i have a 12 bolt olds rearend im in the process of taking it down to bare metal and painting it but before that i want to upgrade the 2.73 gears in there at the moment

i cant seem to find gears maybe im not looking the right way all i can find are complete ready to go diffs can anyone help me with some links?

im looking in the range of 3.55's

would that work good with a th350??

or would i be red lining at like 80mph?

 

Do a search on this subject. I think I remember a post back in December maybe that discussed this. The Olds 12 bolt is very difficult to get diffferent parts for. If I remember correctly, somoene mentioned that this tranny was only used for a few years before Olds started using either the 10 bolt or the corporate 12 bolt. I can't remember all the specifics but like I said, use the search, I am sure it is there.

 

Which "12 bolt" axle do you have? 442s could have come with either the traditional Chevy 12 bolt or the Type O. The Chevy axle was mainly used in cars built in Canada and can be identified by an upsidedown "V" stamped into the back cover. This axle used C-clips to retain the shafts and an 8.875" ring gear held on by 12 bolts.

The Type O has a smooth rear cover and the axle shafts are retained at the outboard bearings. The bad news is that this "12 bolt" is actually only a 10 bolt since the 8.5" ring gear is held to the carrier with 10 bolts. These axles were only used in 67-70 Cutlii and parts can be hard to get. There are no "cheap" gears. One of the best sources is these guys:

http://www.drivetrainspecialists.com...ile/index.html

 

Also try Super Cars Unlimited in Oregon for the gears and posi units. That is if you have the Olds 12-bolt.

 

Your right Dan Super Cars Unlimited is a very good source !!!

WJ

 

http://www.accuautoparts.com/index.jsp its pretty good.

 

Wow, I'm impressed. Have you actually used them? They seem to know the difference between Type O and other axles and list parts for them. Good find.

 

Naw, hav`nt got that far... yet, I have 87 Cutlass, working on the rear suspension, next will be the front. Then i`ll tackle the rear end, going with a3.42 Eaton. Gas prices are freakin me out, was looking into a 455 swap, now im considering a Grand National motor.

 

I have had great luck with OldsmobilePerformance out of the east. Andy Miller the owner has been helping me with the 67 Cutlass fuel system, timing/plugs and cooling system. I would refer him to any Olds owner.