Probably a dum questions ...but will a '57 Pontiac differential fit into a '57 Chevy rear end housing??? A buddy's got a chance to buy one but we don't know if it will fit.
Not sure about those years, but I have a '68 firebird rear in my '54 chevy. I think backing plate to backing plate you should be in the ballpark of about 54"... that's what I had to do with my '54.
The differential housing on a 57 Chevy is considerably smaller than the 57 Pontiac,but if you could find the complete 57 Poncho rear end it should be close to a bolt-in.I have a complete 57 Pontiac rear in my garage so if you need any measurements from it,send me a PM and I'll get them for you. The 57 pumpkin won't even fit in a 55-56 Pontiac housing but the track is the same.
no. the pontiac housing is completely round. the chevy has a flat area across the top and bottom of the housing. jerry