I have two rear ends out of older Chevy trucks that I am rebuilding for an off road truck. The running gear is 8 lug and it looks like a 10.5" end cover. The problem I am having is one of the rear ends is shorter then the other one. If I measure between were the backing plates bolt on one is about 53" and the other is about 58". Can you please help me identify what make and year truck that these two rear ends might have came off of. Thanks for your help.