Sponsored Links (Register now to hide all advertisements)
I think it comes down to what do you have available and at what price? A 9" rear is definitely overkill from a strength perspective, but there are more parts available for 9" Ford rear ends than probably any other made.
However, a good 8" Ford rear is lighter, has all the ratios you could want and there were definitely some that were 5 x 5.5 bolt pattern. Either one will work - just find a good one at a fair price.
. I think a gear ratio of 3.73 or 4.11 would work out fine with your overdrive setup. I would probably choose a 3.73 if I had a choice.