Should be fine.The gasket sits on the flat around the head.p is outside the The lip of the cover is outside the edge of the head..People tend to overtighten these distorting the cover as the area around the nuts distorts and also compresses the gasket too much.Try and tap the area around the nuts from the inside.The retaining nuts only need to be snug not tightened down as much as possible.

  

I have a pair of stamped Mercury script valve covers with new cork gaskets and to me the gasket is only about .015 above the inside and outside rails on cover. Is that enough squeeze to get a proper seal?

Tom

tom in iowa

54 Merc wagon

54 sunvalley