There are differences in the covers of a ten bolt diff and a twelve bolt diff! Nice try Lugnutt! Yea, bolts are one. Then there is that nice twelve bolt Carrier Bearing Oil Flow Wave on the back. The Ten Bolt Covers are smooth. There are also Scallops in the sides of the cover if it is a B.O.P. sometimes. The Twelve Bolt Diff lower two bolts are parallel to the ground!
