my 72 240 has an auto tranny in it,hopefully soon to be a 4 speed or 5 speed.Will the auto tranny driveshaft work with manual gearbox, if not, is there any difference in the 4 or 5 speed shafts.

Don't know about the automatic to stick difference but, I do know I replaced an original '78 4 speed with a '81 5 speed and used the original driveshaft without any problems.

If you have to replace the driveshaft, I highly recommend finding or buying one that has replaceable u-joints. I bought mine from Motorsport Auto and it works well.