In an earlier post, you mentioned custom head gaskets. Can you share who they are being made by? My 273 is being machined right now, and I am using 302 heads on mine. My builder and I were discussing the problems with using head gaskets designed for open chamber heads, and having a one size fits all fire ring. If they haven't made yours yet, maybe they will make 4 of them cheaper than 2 at a time....lol.