rear main leak or oil pan gasket?

On my new motor, I've got 1 oil leak. It runs down the front of the plate that sandwiches between the block and the bellhousing. It does not run down that plate on the inside of the bellhousing, just the outside. Is this a rear main leak or a oil pan gasket leak?

The oil pan gasket is a SCE pro series 1 piece silicone rubber deal. I specifically called them and asked them if I needed to use RTV in the corners or anywhere and they told me that it was designed not to need any. So I only used a smidge where the block, front cover, and oil pan meet. I've retorqued the oil pan bolts, but no luck. Should I just tighten them some more?

As for the rear main, the short block assy is a FRPP piece. It was made in Sep 2000, so it's been sitting for a few years. I called FRPP and specifically asked them if the rear main would be OK after sitting for so long and they told me no problem. So I didn't bother to replace it.

If the oil only runs down the front of that cover, does that rule out the rear main, or could it just be either? Does the rear main, when it leaks, run down on the inside?

Thanks,
Rick

That's what it looks like. There is none on the inside of that plate?

When building the motor, I thought that the rear main might have been leaking, but I just assumed that it was just oil that spilled. I assumed that since there was no crank case pressure it wouldn't have leaked. Can you see the rear main leaking while the engine is getting assembled on the stand? It was on the stand a couple months.

Rick