Well I tried to post before but can not seem to find out where the heck it is to see if anyone answered.
I have a 4.56 8 3/4 third member drop out. Seems to be an original 4.56 geared 742 case... the power loc is also date coded 64.

CAn anyone tell what this rear might have been installed in and what factory cars came with 4.56 gears in 64? Thanks foir the help. Jim