I had an oil leak which I thought was my new valve cover, received new chrome cover from Summit, (have new summit heads as well) installed with new gasket (rubber), started car and notice small black oily film (spot) at rear of head near corner and above last exhaust port below lip. It almost looks like it may be coming from header. I see a small amount of smoke but can't tell if it's coming from the header or valve cover. I can't imagine smoke from valve cover gasket area and it doesn't really look like oil is running out from valve cover. Will a header gasket leak blow small amount of oil out and onto head?