I just noticed you have aluminum heads, are they Edelbrocks? If so did you have them checked or just install OOTB? There should be no oil on valves at all. I am going to guess that either your valves are adjusted too tight, which you think eliminated by comp and leak down but not really if your lifters pump up when its running or a few tight valves that are sticking and probably a few sloppy ones that are leaking oil, or tuning issue-carb adjustment, ignition timing or cam timing.
I would look at Edelbrock first...have had same exact experience with 2 sets hen never installed them OOTB again.
