[MARKDTN]

A short shaft TH350 is the same length as a 3-speed and the yoke is probably the same. But there are several obstacles. 1) crossmember. 3-sp mounts to the bellhousing, TH350 has a frame crossmember at the tailshaft. 2) Flywheel and you need a flexplate 3) starter. You will need to go to a block mounted starter on a 6-cyl.

Might be cheaper and faster to fix the carb. I'd spend my money on disc brakes.