^^^ surprisingly theres been 5-6 listed in this forums classifieds over the last year or so. not all 6bt's, but cummins swaps, some even 4wd. most of the ones I opened were no longer valid links so I didn't repost here, but a search yielded a handful pretty quickly.
not 4x4, but this one was at the top of the list ...
"understeer is when you hit the wall with the front of your car, oversteer is when you hit the wall with the rear of your car, horsepower is how hard your car hits the wall, and torque is how far your car moves the wall."