I had set of the " cheap " fabricated valve covers blew out a gasket top end of a run , the bottom of the cover was flat with no provision to hold the gasket in place. I have been running a pair of the Mopar Performance cast covers for years with no problems and they aren't flat on the bottom so the gasket stays in place. If I could find a set of fabricated covers that aren't totally flat on the bottom and have an area to hold the gasket in place I would consider getting them for my small block.
I would be worried about blowing a gasket out, that is a lot of pressure maybe showing other problems. But, those fel pro gaskets I mentioned are basically two cork gaskets sandwiched together with a thin steel core so it would be much harder to push them out. I have been reusing mine for years.
