Oil pressure isn't the problem. Proper sealing is the problem. I've been running RTV on my 71's Ebrock intake for over 2 years with no leakage...and no turkey tray at all.
Preparation! Can't get the surfaces clean and oil-free enough! Clean it two or three times. (Obsessive/Compulsive that I am).
Use enough RTV. I layed on a thin bead, working it into the "keeper holes" and those weird side angles, let it skim, layed on thick and wide bead, let it skim, layed on a thinner bead, let it skim, and even a third thin bead and let it skim before even thinking about putting on the intake. I believe I even used a straightedge to check the height. (OCD again!)
Don't "push" the overflow flat....it'll just glop into the valley and unseal itself. Wait a few days and cut it down with a knife. (It was really hard to wait!)
Do you have a PCV problem that might be blowing the seal?
These were a few random thoughts whizzing through my empty head. No OCD this time....just crazy!
C.J.