Ford used a Spicer 50 in those years which was a very good rear end. They came in 3.54 and 4.11 ratio. Even though the 8 hole bolt pattern is the same as GM, you will have to use Ford wheels because they had a slightly larger hub than GM. Ford wheels will fit a GM, but GM won't fit a Ford. If you have the 3.54, you are lucky. The 4.11 was much more common.
