1972 Buick Riviera Rear Axle

Yes, you are correct. Welded shut the Seville caliper mounting plate mounting holes and drilled new holes to match the '71 Riv's axle flanges.

 

cool you got that to work for you.

 

Montaz all the info you stated is correct minus one thing.. the pontiac rear is not a bolt in axle.. it is 31 spline C-clip. Side spider gears are the same and interchangeable though with the olds 9 3/8

 

ALL 1971- 1976 are BOLT in axles for FULL size BOP - Chevy may have had a version or the rear is a newer 1977-1985 31 spline c-clip rear. 10 cover 12 ring.
A-body 73-77 also had a 31 spline 10 bolt cover 12 bolt ring pontiac rear that had the smaller 1.625 pinion shaft...Monte Carlo, regal, cutlass etc.

You have to remember the age of your cars and the likely hood original drive line parts are still in it from 40 years is NOT likely. Jim

 

Jim .. not true the 71-76 fullsize pontiac 8.875 is a 31 spline C clip. Sorry for the late reply i dont get on here often

 

True!
I snagged a ‘71 full-size Pontiac POSI rear for my ‘75 Electra back when. It had C clips.

 

The last one I worked on was a bolt-in axle,but when you got to the late-70’s,everything was phasing into a c-clip.

 

I have a pair of 31 spline c clip axles on the shelf. Jim 5 on 5 bolt pattern