Minimal leak during cruise at 3400 RPM. Very obvious and a nuisance at RPM over 3800 RPM. I've tried Permatex brushalbe "aircraft" sealant and high temp RTV on threads and base of intake bolt heads. The 2 center intake bolts beneath the carb on the starboard side of both motors give me the most grief.

Is my crank-case ventilation not effective enough? Wrong breather system on valve covers? Wrong sealant? Any suggestions are welcomed. The motors are 509"/550hp with 200 trouble free hours. Thank you

It may be a fuel leak that has been pooling on a hot intake manifold for a while. Eventually, the fuel ends up looking like oil. This had me chasing an oil leak that ended up being fuel laying on the intake manifold.

....just my experience.

Good luck.

Definitely oil.

Is the oil creeping up past the threads of the bolt?
Are you sure it is not coming from the valve cover and winding up on the intake?

I believe the oil to coming past the threads. In your experience is this not possible? Maybe I should replace the valve cover gaskets or pull the covers, clean, and RTV the existing gaskets. Thanks

We had a similar scenario with a 454 in a pickup - pool of oil looked identical to your picture. We re-set the Edelbrock intake and sealed the center bolts - no more oil.

Ironically, it was also an Edlebrock RPM intake.

Have you checked inside the air cleaner to see if it has oil laying in the bottom, I had that problem awhile back and it dripped down the right side. I changed my crank venting and fixed the problem.

Phil