HevyHauler, I was initially looking at the NV4500 pretty hard until I found this:
Novak Jeep Conversions Knowledgebase: NV4500 Since then I've been looking at the AX15, although it is only listed as a medium duty transmission. My 1951 4400 1.5 ton won't be used for max effort hauling and the engine is probably going to be a 292, so the AX15 shouldn't be overpowered. The drawback is the cost of the adapter.