One of my all time favorites is 5th gear! (one rear off of the ground and no parking brake set, but you'll be able to grip the tire on it's OD (like a 15" breaker bar!) and turn through the tranny with something akin to a 1.43:1 mechanical advantage (Overdrive backwards)... a bit of a long reach from the rear wheels though - you may wanna use 4th gear (1:1) so you can tell how far you've turned the engine!

Worked in a FWD shop for a few years and used to spin all my valve sets that way...