[Mike C]

If money matters to you as much as me, the only answer is an SM465 and the NP205 IMO. With the torque of the 496 you can gear the axles to cruise whatever RPM you prefer and the granny gear gives you good off-road chops still. Any truck through the early 80's with the SM465/NP205 would be a good donor. Shouldn't be more than $500 worth of transmission parts. Driveshaft mods will most likely be needed as well as clutch linkage fabrication because of the non-OEM placement of a big block in the 4x4 trucks.