I have measured my frame on my 62 and so far it looks like a match to the newer frame. I had originally thought I'd have to do a frame swap. This is going to be less hassle by far. Answers like these are why I belong to this site
If at first you don't succeed, get a bigger hammer.
1941 Pontiac business coupe 1947 Chev Coupe 1969 GTO ragtop
