ok so i went out to look to see 4 sure what rear end i had... well it looks to be a gm 10 bolt but it messures 11" wide??? is this weird or was this an option in 1989?? go here and there is a pick of what it looks like http://www.powertrax.com/diff.htm it is the one at the bottom far left 8.2", 8.5", 10 bolt holes, 11" wide anyway can someone help me figure out what i got here? and what i would need to know about it to swap gears into it thanks corey..

 

oops i didn't see the other topic had "weird" in it also ohh well mine isn't really weird just confusing

 

It's a 7.5/7.625.
No one in their right mind would swap in an 8.2 and the factory sure didn't do it. It should have an oval cover.
What that site gives is the measurement for the cover bolts center to center one side to the other.