I've been pricing used ring gears, pinions and posis to install in my 8.5" 10 bolt rear end. In looking at the different ring and pinions, I see the term "corporate" 10 bolt used. What does this mean?

It is a 'semi floater' 1 ton truck differential and is produced by corporate GM. Very big and very heavy not to mention very strong due to its spigot bearing support on the pinion shaft itself.

Thanks! Any fit issues going into an 8.5" 10 bolt? The rear was originally in a '72 Nova.

Yup, the ring gear is 2 and a half inches larger than your 8.5" differential. Basically, if you are trying to fit these two together, they wont even come close. The corporate 10 bolt has a ring gear diameter of 10.5" and is much larger than anything related to the 8.5"

The 8.5 is also called a corporate rear end. Each division of GM had their own rear end at one time, untill '71 when the 8.5 was used in all GM cars. The parts that you are seeing are probably for the 8.5 corporate rear end.

Or there is what Freddie said......

Most corporate differentials were described as a 'corporate.......so and so'. Most of the passenger car diffs were described by their respective ring gear diameter. But BGH has brought an excellent point to this and that is that they are known by both.

Oops on my part, I shouldnt of left that part out. I agree that you are most likely looking at 8.5" parts and no the corporate 10 bolt, 10.5".

Thanks guys! You've both been a great help!