use sealer on the bolt thread and on the bolt head flange as Jim suggested...and like you already meantioned most important is has to be super clean before you apply the sealer...bolt AND thread. I sometimes use brake cleaner and an air gun to get it clean. spray into the air guns blast with the brake cleaner this way it dries immediatly and you can put the bolt right in before the oil keeps coming back
Check pcv valve. Clean area and bolt with brake cleaner. Use a good amount of RTV on the bolt and under the head. Tighten. Wipe away excess. Let cure for 48 hours. Better yet, hook a shop vac to valve cover. Push the RTV into the bolt hole as much as you can. Install bolt. Wipe away excess RTV. Remove shop vac. Allow to Cure 48 hours. Shop vac will pull RTV into problem area for a better seal.
I cleaned the entire area with brake clean, then removed both front bolts, cleaned it again, used some right stuff on the bolt threads, and under the heads. Then I smeared some along the gasket line. Looks nice and dry now. I'll have to see when I drive the car next. The Cruise nights have been rained out for 2 weeks in a row now.
Haha ive broke more by hand actually than with an air gun. Im an expert at drilling out broken bolts and helicoil inserts. I also got great expiearance when I removed and rebuilt an Atomic 4 flathead in a sail boat. I prettymuch borke every bolt on that thing.
