Diesel engine swaps

I don't know what a C body front clip measures at the front K frame mounting points, but a Dodge pickup frame is 38-1/2 inches wide across the rails. I would be looking at the possibility of the front of a Cummins D250 frame section with suspension at this kind of weight and some 16 inch eight lug wheels with the Dodge hubcaps, front and rear. For rear axle choices you could go with a Dana 61 semi floater, 14 bolt GM semi floater, or Chrysler 9-1/4 8 lug (two wheel drive 3/4 ton semi floater from eightees). I’d look for one of the positive retention axles before going with a 9-1/4, unless custom axles and Dana 60 housing ends are in the plan.