olds rear end questions

I see alot of guys saying to find a 57 olds rear end for a gasser
why 57?
whats the difference from a 58-62?

 

As I read some where ... the 57 has leaf springs and the later ones have coil springs. I also think the internal stuff interchanges ... to 62

 

At least on Pontiacs, the 57-58 are a narrower rear end. 57 leaf, 58 coil. It inter changes up to 64 except the earler axles have 29 spline and the later have 31.

 

http://www.jalopyjournal.com/forum/showthread.php?t=129676

There are other threads out there too.