It's going to take a ton of work to put a completely foreign motor and transmission/transfer case in one of these vehicles, so I don't think it entirely matters what you put in - a Ford 5.0 is probably going to be as complicated as a cummins b-series, so at this point it's about what's handy and what level of investment you're planning to reach with your rig.
I personally believe that these vehicles are heavy enough to warrant the use of a motor that was in a heavy duty truck. If I'm not mistaken, the original IH gas engines showed up in smaller dump trucks.
Then the driveline - what will pair with your motor and the intended axles (stock d44 ratio maybe?) to give you a desired cruise rpm? If going automatic: will the transmission be from something heavy enough that the torque converter is designed around it, or will you need a custom unit to "match" your motor's power production to its load/gearing? I guess that problem disappears with a standard tranny... But will the unit you're using have the right clutch/gearing to see long life behind x or y engine?
Lots of questions, but I could be nitpicking. If you pull every foreign component from a vehicle of similar weight and retain close to stock gearing (this includes tire size), it shouldn't be much hassle. I just don't know what the 5.0's were in... Besides 5-speed mustangs.
Whatever you choose to do, please keep us posted with a reader's rides thread.
