Hi, I thought I saw a thread here a while back that said there was a inch or so difference between a 65 and a 67 in width of the differential (drum to drum) or may be it was gto to chevelle? anyone got the answers? thanks, Cliff

64 to 67 is 60" wide overall. 67-72 is 61" wide. Donīt now if itīs the same for Pontiac. But you can mount in any rear 64-72 but you will need to check for tire clearence. Have a chevelle 64 with a chevelle 70 12 bolt.

Marcus