I need help identifying these rear ends. I was told that the one on the left was out of a '54 3100 and the one on the right was out of a '57 3100.

Any help?
Photos of rear ends


'53 Chevy Pickup, 235ci, 4 spd Saginaw, Fenton Headers, 2x1 Offy Intake, Monoleafs dropped front springs, 15" rally wheels