Anthony P.
I've never installed a creeper, but, i have replaced a worn out driveshaft. The Driveshaft does wear around the clutch springs and TO Bearing. If you haven't already torn into it, you may have to tear it down and inspect it to see how much is left. Maybe someone else will chime in.
Oh, you don't take the tranny off, but you do have to loosen up the engine and slide it forward, i think there is a procedure on here somewhere for that.