To the best of my knowledge there isn't a tail shaft housing/rear bearing carrier made for your 1936 transmission to make it an open driveshaft. Since you're swapping out the rear (I assume you're getting the springs and hangers with it) and the engine, why not put a more modern trans in as well? If you're keeping the original trans you should keep the original rear.
Are you upgrading the front brakes to match the Colorado rear brakes?
Mike B
