Troublesome Oil Leak

Thanks everyone for the helpful replies. Almost certain it was the china walls, found oil in the corners when I tore into the engine today and got the intake off. Used damn near a whole can of brake cleaner degreasing everything. I switched from the gray gasket maker to the ultra black RTV, and I made sure to do a more thorough job overlapping the corners under and over the intake gaskets. Fingers crossed I don't have the pleasure of trying a third time.