Correct Oil Filter for SB

That leak seems more like what I would expect of a rear main seal leak. At this point, I'm stumped. BTW: Nice looking engine (from what I see in the picture).

There are two oil gallery cups that seal the front end of the cam lube passages that are located behind the cam thrust plate. The front of the engine needs to come off for that to be checked. The only other place I can think of is the seal between the oil pump and rear main cap and block.