Make sure that the input shaft fits into the pilot bushing and also measure the length of the input shaft tip and the depth of the pilot and hub on the crankshaft. have seeninstances where the input shaft tip had to be trimmed from butting up against the crankshaft and not allowing the transmission to fit up to the belhousing.

Clean it, if it's Dirty. Oil it, if it Squeaks. But: Don't fix it, if it Works!