So I'm putting the engine back together on my cl360. I bought a brand new complete engine gasket kit. However I have a question...I don't have a gasket in my kit for the last piece of the top end. See pic below. And there wasn't a gasket in there when I pulled it off. Rather there was a gummy like substance on it? Does this piece not use a gasket? And if no do I need to replace the gummy stuff?