Thanks for the replies,
I don't have the chassis tag right in front of me, but if I remember correctly it has the less desirable model tranny with no OD. I'm guessing it probably is the AT545.
I have no qualms punishing it until it grenades and either replace it like
this guy did, or getting what I can for the rolling chassis and powerstroke when it dies.
The bus was only $1000, so it would be difficult for me to find a truck that is running for that price. Even with a smoked trans, I'm guessing the engine and the frame is worth that to somebody.
A locking rear would be key for this project though, for sure. In my experience a locking rear 2wd is superior for traction in slippery conditions that 4wd and an open diff. Any idea what the going rate for locking gears is on the used market in the Northeast? I love the truetrac style gear-based lockers.