Don

Its probably not the seal leaking unless----block has been align bored and the caps were cut severely

If you have the pan off, put a little dab of silicone on the ends of the main cap where they go over to the pan rail

Make sure its not a oil galley plug, camshaft freeze plug or even a leak from the manifold thats running down

A oil filter leak can run back along the pan rail and look like a rear seal

There also have been cases of high pressure/volume oil pumps spraying bypassed oil stream over to where the gasket wasn t sealed

In other words----good luck