Valve Cover Gaskets for Fabbed Aluminum

Now that I've gotten a few miles on the car, I still seem to have a valve cover leak. Thanks to the great new technology of smart phones, I confirmed it! Question is now, whats a good gasket to use on these valve covers that seal well? I going to tighten them up a bit more to see if it remedys the problem, but was wondering if anyone else on here has had luck with other gaskets?

BTW im using some fel-pro hard black rubber gaskets from a 85 dodge 318 truck if that helps. Oh and FYI, seems to be bad when 3/4-full throttle, otherwise, dosn't leak