What's the story on the engine? Rebuild? I fought a rear main on mine for about 2 years after I rebuilt it, small block. 3 seperate times I took my trans out, once I siliconed the cam plug, once I changed the rear main in the car, no improvement. Finally I yanked the engine, and changed to a rope seal.

Here's what my problem was, the crank was wore where the seal was suppose to seal. I happened to have a brand new crank to measure, sure enough mine was about .010" too small, so it wouldn't seal. I tossed the rope seal in it, no problems since.