so my valve covers aren't perfectly flat and i used the gaskets from my felpro top end kit which happen to be cork. i'm still in the assembly stage of my engine (last steps) and so what i did was poured some oil over the cylinder heads before i put the valve covers on, then when i put the gasket/cover on, i tipped the engine to the side a bit to make doing the other side slightly more convenient - oil leaked out. so i'm wondering if this will be a problem when it's in the engine straight up and down. should i take it off and use one of the rtv sealers? what type should i use?