55-6-7 all had the same basic frame, coils w control arms in the front, leafs in the back. This month's{oct} Super Chevy has an article on improving the handling in a 55, lots of pics you can see
what it looked like stock. Chevelle frame is most likely wider but it
might fit, ... money would be better spent on something that WILL fit. Agian SUPER CHEVY is a good source of pics and adds for stuff for these cars....just my 2 cents worth