BIG Oil Leak Options

[Fastbird]

Ok guys, time to fix this. I've had a LARGE oil leak on my Celi for quite some time now. It's odd though, because I can't find it! Here's things I've just checked again:

Pulled the Distributor, no leak, no sign of leaking, O-Ring is fine, inside is dry.
Valve cover has residue along back side, but it's NOT the leak as the residue is dry.

The only things I can think of are it being either the oil pan gasket, head gasket, or the rear main.

My problem in tracking it down is that I have all the undershields off of the car and it's blowing the oil everywhere. Around the front and back of the motor, up on top of the tranny, ect. I'm leaning on the oil pan gasket right now because there's a LOT of residue along the pan rails and some cracked silicone in spots, but the oil on top of the tranny leads me to think otherwise. Good news is that I'm pulling the pan right now to have a 1/8 NPT bung welded in to relocate my oil temp sensor.

Just throwing a feeler out there, seeing if anyone has any other ideas..........as I'm stumped on this one. I know the distributor o-ring is notorious for leaking, but trust me when I say there is ZERO evidence of a leak there and I've thoroughly inspected it today and the seal is fine.