I have a 1967 Delmont 88 with an O-type rear--12 bolts on the cover and, what I'm told, 10 bolts on the gear.

Does anyone know which other B body rear ends would bolt in easily--same spring perches and mounts, etc.?

Right now I'm finishing the engine, body and interior and, to stay married, will probably not be buying a rear until next spring. However, I would like to know which rears would bolt right in and will keep an eye open.

Thanks,
Chris

 

There's a site for this conversion and I can't find it anymore (dont remember name), someone knows this though .......Im reading ATM will post back

 

Is your Delmont an original 330 or 425 car?
They used different rearends.
A pic would be helpful.
As for swaps, any 65-70 full size Olds will bolt in (but you might need to change the yoke or U-joint and/or driveshaft length).Not positive on other divisions B & C cars.
Depending on which rear it is, it might be easier to swap in a posi differential than find a whole rear.

 

Thanks for the replies!

It is a 425 car. I would swap it out with a posi differential but they seem hard to find.

 

Ok - There are BIG differences in the A-body to Full size 12 bolt covered OLDS rear

A- body 12 bolt olds has 12 bolt cover (kind of LOOKS like the full size olds 12 bolt cover BUT the full size cover is much bigger in diameter)
A-body 12 bolt olds (found in Cutlass, SX 442 etc.) has 12 bolt cover and 10 bolt ring and pinion.

B-Body FULL SIZE cars 88 98 Etc. will also have the round 12 bolt cover BUT will have 12 bolt RING AND PINION unlike the smallewr A-body 12 bolt cover rear.

A-body ring diameter is 8.4 advertised as 8.5 in all the ordering forms in the aftermarket world and has 3.42 and 3.91 gears available from Richmond Gear.

The B-body 12 bolt rear is 9.3 ring diameter...MUCH larger than the A-body OLDS rear There are NO AFTERMARKET GEARS FOR THIS REAR. PERIOD.

I do have a Posi and 2.93 gears set MATCHED for your car BUT they are not easy to find which makes them much more expensive. PM me I will give you the price. Please be seated when reading it. LOL

Here are the pictures of each.

I KNOW THEY LOOK THE SAME BUT WHEN YOU PUT THEM SIDE BY SIDE THE SIZE DIAMETER IS A BIG DIFFERENCE AND A A-BODT REAR WILL NEVER FIT IN A B-BODY REAR AND VISE VERSA... THE PHYSICAL MOUNTING POINTS ARE NOT EVEN CLOSE.


J D
Jim

 

Donor carrier for the Big 12 bolt is the 1971-1973 Riviera. The Riv came with 3.07 gears as standard issue with optional posi & the Riv GS came with 3.42 gears with posi. Over on the Buick board some years ago there was a push to get 3.73 gears made for this carrier but I do not know how that worked out. At the time I had a 1969 Olds 88 Royale but sold it when I got out of the big cars & lost touch with that forum.