Rear axle idenification ?

[wilberweb]

Hi, Guys.
I just installed a rear axle in my 55 Chevy 3100 second series 1/2 ton pickup.
I finished installing my camaro front clip. I got this rear deferential from a friend. He said its out of a camaro or a chevelle. I'm not sure what its out of. I thought maybe some one could tell me. I have a number off the axle of ARG72542 but no match on line. It had some bushings on the top of the housing for some arms. I cut them off. I took some measurements from the camaro inside wheel it came out to be 54-1/4" then i took the same measurements at the rear axle it came out 54-1/4" so I think it maybe a camaro rear axle. But I want to be sure. Here are some pictures.maybe some one may be able to tell.

Thanks all
-Larry