I have a 72 FJ40 that I am attempting to rebuild. It has a 1986 Chevy 350 that runs pretty well and the original 3 speed stick transmission and T case. I really need a 5 speed and have been reading about the various transmissions (NV4500, H55f and R151f) that can be used. I am leaning toward the NV4500 because Advanced Adapter has a conversion kit where I can use the original T case. Does anyone have an opinion on which way to go?