Allan R

Will a posi carrier from a 72 full size Olds/Pontiac/Chevy fit a 8.5 corporate rear for 72 A Body?

There's one up for grabs with the following details:
8.5 posi carrier, 12 bolt ring, 10 bolt diff cover. Will fit 2:73 or higher gears.

Is this something that would work on a Cutlass or am I stretching???

442Harv

NO, will not work

leadfoot067

why wont it work? 8.5 is an 8.5...regardless of what housing it was in...only diff may be the spline count on the axles.most were 28 spline..some later chevtruck stuff was 30 spline...but the big car may be 30 spline...not sure..

Allan R

This is the same thing that I was wondering. BTW the spline count is 28.

joe_padavano

First, because I believe the full size cars did NOT use an 8.5" ring gear. Second, even if it is an 8.5" ring gear, there's no guarantee that the dimensions and bearings are the same. The Type O axle also uses an 8.5" ring gear, but it is NOT interchangeable with a corporate 8.5.

Allan R

Ok, that's what I needed to know. It just seemed like a heck of a good deal for 20.00

The unit is for full size cars and came from a Pontiac. Seller does say it's interchangeable with full size Olds, Buick, Chev and Cadillac.

Allan R

Joe,
The seller says this had 3:08 12bolt ring & pinion. From a non mechanics point of view, wouldn't it also be able to mount a 3:23 or 3:42 as long as the ring gear was 12 bolt?

Eddie Hansen

I think you could mount up to a 3.90 in a 3 series carrier, but originally it was stated a 2.73? I think that would nmean it was the smaller carrier and could not mount the 3 series gears? I know that the 69 "12' Bolts on the cover and 10 bolts on the gear. but this changed in 71 I think. Jim at jd race is probably a good source of info on this as well.

joe_padavano

Let me try this again. This carrier and associated axle have NOTHING in common with the more common 10 bolt and 12 bolt axles. The fact that other gears have 12 bolts does NOT mean that they will bolt to this carrier. More specifically, if you think you can get a gear set from a 12 bolt Chevy axle and bolt it up, you are sadly mistaken. The reason why this carrier is only $20 is because it can only be used in the 1971-76 B-boby cars, and parts are virtually nonexistent. Where, exactly, did you plan to get the 3.23 or 3.42 gear sets, because they don't exist in the aftermarket.

Allan R

Easy there Joe,
Like i said, I'm not a mechanic. So thank you for the explanation. It's an apple and I need an orange or something like that. I get it. As far as the 3.23 or 3:42 non existant gears, I was just asking. Didn't know they didn't exist. Anyway from the input, I decided I won't be buying this carrier. I'll get in touch with Jim and work something out for my posi needs. I know he'll steer me right, he's given me excellent advice in the past.

Wish I had your technical knowledge.