Oil Underneath Intake

Fabricated aluminum valve covers? If you used the bolts that came with, the leak is probably from the VCs.

I found the cheap bolts that came with mine were stretching. I was running them snugged down and was getting oil in th valley. It was only after I actually tried to torque them and one almost broke.
I ordered new bolts, washers and used a ream to open the counter bore up to 7/16 for a thicker ss washer
Bolt - McMaster-Carr
Washer - McMaster-Carr