[Mickey_D]

What I think would be cool as all get out would be to mount it in the bed (I mean in, not on. Partially submerged would be a good explanation) and run it mounted backwards (flywheel forward) then have the driveshaft run forward to a transfer case flipped backwards in 4lo (to double the engine's output speed), then have the prop shaft run back to a flipped axle.

You've definitely got enough torque there to to run in 2:1 overdrive, and that would get your powerband up in the 60mph range (I would think).

Then just bolt in a non-operational 260 V-8 out of a 70's Cutlass or something ridiculous like that as ballast and for the head scratching effect. Fashion up a hinged hard cover for the bed to hide everything.

As for shifting, take a look at how the old Diesel pusher school busses work it all out. They've got the driver at the front of a 40 foot long bus and the tranny at the very back. If they could do it there, you should be able to copy it for the relatively short distance for yours.