I've been told by some old timer Ford guys that the exhaust manifold and heads were metal on metal originally and if you put any gaskets on they'll just burn out eventually. The intake to black definately had gaskets though. I've been having a similar oil leak to what you're desribing, and thought my valve covers were leaking so I rigged up some tension retainers from my many 350 rebuilds since the covers are a prro design for proper sealing. This did not fix the leak and bent the hell out of my covers!! Live and learn, but I still have something leaking on the back side but not actively enough to spot the problem spot or make the level go down significantly. My 64 Gal is still in storage for the winter but hopefully I will be able to get back there better this year and hunt down the prob. if you find the culprit please post it.