Before you tear into the motor make absolutely sure where the oil is leaking from, it can leak from the rear main seal, one of or both of the rear oil galley plugs or the cam plug, the rear main seal holder can leak out of the sides alao looking like it is the seal when it isn't
One motor in particular the guy had the oil pan off four or five times before someone else saw both valve covers leaking from the rear corners dripping down onto both rear engine ears and then blowing back into the tranny dust sheild
I've seen more than one "main seal" oil leak turn out to be not that
If it is the rear main seal itself leaking the oil will be slung off of the crank shaft flange onto the front of the flex plate or flywheel and then slung outwards leaving a distinct pattern of straight oil lines from the center of the crankshaft flange
Good luck, let us know what you find