Also, since you are already using open drive rear end the T-5 swap will me much easier. The 3:55s or 3:70s would both be super with the T-5 od. The T-5 is the best mod I've made in my pickup, just shop around for the right one. Also contact www.stoveboltengineco.com he had some rebuilt units earlier in the year.

It's easier to get forgiveness than permission!
1946 1/2-Ton Chevy
1953 Chevy 3/4-ton Factory Stakebed