Going from auto to 4 speed isn't a simple thing. First off, you need to make sure your 360 is able to be used with a 4 speed. If you are using a factory Mopar 4 speed, the nose of the input shaft sits in the rear of the crank, supported by the pilot BUSHING you're looking for. If your engine was originally built for an auto, it may not have been drilled out for the pilot bushing and the tranny simply won't bolt up. Unfortunately you won't be able to know this until you pull them apart and examine the rear of the crank.
Once you do that, and say you do have a drilled crank, measure the inside diameter of the hole. Then do a little research to make sure you get the size bushing you need. By 78 they may have changed the bushing or it may have been a truck engine or something. Better to confirm than get stuck with parts you don't need. Btw, Mopar used a metal bushing back in the day, not the roller bearings you see today.
If you're using a non Mopar tranny (I have a Tremec) then they do have pilot BEARINGS that can be used. The trannys are modified to have a shorter shaft and can be used with auto crankshafts. Hope this helps, good luck.
