the valve cover gasket sounds like someone was up in there and didn't tighten the valve cover down tightly enough. admittably that is a very narrow margin..has anyone been in there for other reasons or did this just start of its' own volition? cause if you do 'overcompress' a valve cover gasket it will leak...i've seen/done it.....typically 9/10 ft/lbs for the valve cover bolts would be normal....virtually nothing....but you would really have to screw this up if you took the head cover off, did whatever, and then replaced the cover without doing these other things...really...to have oil leak out of it all of a sudden? hopefully someone else did this or it's something else (could be) or you did it yourself...something's up eh?