OK, thanks everyone for all the help.

I installed a new MLPS and though I could only drive it briefly, it seems to be shifting a LOT better. It no longer bounces back and forth between gears and it seems to be actually driveable without manual shifting.

A couple things:

It still seems to be shifting too early, or maybe the torque converter lock is engaging too early, it seems to kind of stumble on takeoff with this. Could this be caused by the bad low range switch on the transfer case? Or the vehicle speed sensor? (the speedometer reads correctly, could the VSS still be bad?)

Also I must've messed up the shifter cable as the needle on the stalk is no longer over the correct letter. I didn't see an obvious way of adjusting this. Any tips?

Thanks for all your help everyone.
-Ben