I came across an NOS Offenhauser alum valve cover for my 216 (53 1/2 ton). I noticed the new valve cover doesn't have a vent slot in it like the original does. I assume that some air needs to be drawn into the valve cover somehow.
1. How critical is the venting, and if my current oil filler cap, (the flat kind with locking tangs) shouldn't be used, does anybody know a source for another suitable cap? I guess the chrome push-on caps are a possibility.
2. When replacing the valve cover gasket, is Permatex or some other sealer recommended? If so, does it go on the valve cover edge, the edge of the block surface, both?

Thanks