12 bolt??

GrtDanes · Poncho Master!

12 bolt??

66 Beau · Poncho Master!

I think your rear end us 57.75 inches wide whereas I think the Cutlass is likely 62.5 inches wide. That's a pretty significant difference.
Also, check that Olds rear end. Olds had a housing with 12 bolts on the cover, but only 10 on the ring gear. If that's what you have, it's not a real 12 bolt and won't be as strong.

seventy2plus2 · Canadian Poncho Superstar!

Here's something to watch for, that 12 bolt in the Cutlass may be an "Oldsmobile" only 12 bolt. There's a 67 Cutlass Supreme in Buck's Auto Parts here in Calgary, and while the cover has 12 bolts on it, I'm sure it's different than my 12 bolt differentials - The cover is much more elongated. I'm familiar with the Chevy 12 bolts, as I was working on my diff out of the car (1969/70 fullsize) just a few weeks ago.

Also, the 10 or 12 bolt doesn't necessarily mean how many bolts on the cover. It actually means how many bolts on the ring gear.

ARCADIAN · Poncho Master!

Cutlass has trailing arms and coils, Acadian has leaf springs. You will need more than a saw!

-- Edited by ARCADIAN on Monday 9th of June 2014 07:44:00 PM

4SPEED427 · A Poncho Legend!

GrtDanes wrote:

Would a 12 bolt out of a 69 cutlass fit my 67 Acadian with a little massaging with a saw?

The only original GM diff that offers any hope of fitting is the one from a 67-69 Camaro/68-71 Nova and even it's too wide if you want to put anything more than a skinny little tire on. I have heard guys talk about a particular Ford diff that is narrow enough but I forget the application.

Chances are the 69 Cutlass 12 bolt is the good one (if it's from an original Canadian car) and is well worth picking up. They fit Chevelle, GTO etc and are very much in demand. If I get a chance I can post a picture of the cover off the "good" 12 bolt. The cover will tell the story, as the "bad" 12 bolt does not share the same cover.

JERICO · Addicted!

My Acadian has a 'narrowed 12 bolt coil spring rear'. The ears(trailing arm attatch points) are visable and the Panhard bar is fastened to one.Tubes are welded. This was in the car when purchased.Has all Mark Williams internals.

4SPEED427 · A Poncho Legend!

And yes, that is exactly the cover to look for to find a guaranteed actual 12 bolt ring gear.

GLHS60 · Poncho Master!

That cover is designed to supply lube to the carrier bearings. Not all aftermarket covers have the formed in eyebrows and can lead to problems.

Thanks
Randy