bowtie81 said:
Got this link from tommy, this should answer your question.
http://www.oldsmobility.com/old/10bolt-tech.htm
First dot on that site is already wrong. lol.
Truck carriers 1974-2011 will fit all 8.5 cars 28 or 30 spline.
Second bullet is AGAIN wrong 56.5 is NOT the flange to flange for the 64 65 66 it is 54.25 - 54.5 they are 59.25- 59.5" over all drum to drum. 1967-1972 were all the 55.25-55.5 60.25-60.5 drum to drum
Then the next bullet they say that the 12 bolt guts from truck will not fit the 12 bolt guts from the car. YES and NO the posi and open carrier case are not interchangeable BUT the spider gears and clutches are in the open and posi ...lol.
SEE what I mean YOU have to dig deeper. When all you do is rear diff stuff day in and day out ...we just roll our eyes and laugh at the info out there... 1/2 my business is fixing other people blunders where they bought the wrong parts and installed the wrong pieces the wrong way.
pretty sad cause they got SOME info from the net...NOT ALL of it.
There are SOOOO many sites with BAD info out there you really need to be careful. There is no way you can ever write down ALL the different configurations out there and beside this rear is not original to his car or a g-body it most likely has been chop cut welded upon etc.
You can use the sites as a guide but be VERY careful how far you trust them with the info.
Hope you post the pictures to determine exactly what 10 bolt 8.5 rear you have.
It is 10 bolt 8.5 absolutely.... But it could have bolt in axles c-clip axles could have 28 spline axle 30 spline axle...and so on.
Good luck, Jim