Frustrating oil leak!!!

[Red68]

I recently rebuilt my 327 small block and I have an oil leak. It is coming from the back drivers side of the engine. I removed the new valve cover and noticed a little oil under the gasket so I applied some gasket sealer and thought I fixed it, apparently not. I can see it drip/run somewhere from the distributor to the edge of the block where the head sits, just above the oil filter. I have checked the seal between the intake and the block and applied some sealant with my finger, I cannot feel any fresh oil in the intake area.

I have used a small mirror to look on the back side of my engine and cannot see where it may be coming from.

could it be a crack in the block somewhere that would allow it to leak?

Anyone have a similar problem that may have a solution?

Thanks