It makes things a bit simpler if it is a 2wd. 4wd is a crap shoot as to the better way to go, but the 4R100 would still have to go. The claim is that the Ford diesel trannies don't hold up, but it also depends how crazy you are going to go with the motor. Also, a consideration is the bell housing mounting, it may be more trouble to get an adapter plate made. They are available for the diesel bells, but not as much for the small gas bells. I don't imagine they kept the bell the same as the 302, but even then, it limits the torque converter size, and the gas converter won't work well with the Cummins.