Hank, I have scanned a picture from the shop manual, take a look at it. There are two plugs in the rear of your engine that could leak oil, a pipe plug and a camshaft bearing plug. Oil coming from either of them would leak to the rear of your motor and make it seem like the rear main was leaking.
Also reach around the back of the head and make sure that the valve cover gasket is not leaking. Unless I glue my gasket to the valve cover I have trouble with a leak in that area.
I hope this helps..
Plugs at rear of motor
