I have seen articles on two Power Wagons with Cummins stuffed in them. One was done by a private party, one by Dodge/Ram. The effort of the private party actually looked to be better done, and the owner was happy with the end result. I guess there is s reason why Dodge went to bigger differentials for the diesels than the ones used on the Power Wagon, as the smaller ones were used on the diesels in the past. I am sure there are ways that you could overcome the torque impact electronically, although common sense and a light foot would no doubt help. I plan to add a front locker to mine in a year or so to help out off road. I think a big issue with any diesel pickup offroad is the extra weight of the engine.
Power Wagons have very low axle ratios and should be able to handle 35" tires with no modifiactions to the suspension and 37"s with a 2" lift puck on top of the springs in the front.
I would have to look at the new Ford Raptor as well, it really seems to be set up for off road right out of the box.
