just questioning transmission

well i really didnt have a big worry about the transmission that i would be putting in my 2001 alero gls 3.4l but i went asking around about how to do the wiring and they keep wondering how the transmission is going to fit or something like that. well i was wondering how much bigger is the 4t65-e over a 4t45-e (alero) as far as the driveaxles going into them.