AMC Model 20  
Perfectly round rear cover with 12 cover bolts.
Has bolt in axles which are a 2 piece design from the factory.

AMC Model 35  
10 bolt rear cover, earlier designs used bolt in axles then switched to c/clip in 1990. Newer Grand Cherokees went back to the bolt in design. Was also used in some front applications in both standard and reverse rotation.