the head I have is aluminum so I took the head gasket and a scribe marked over pistons then took a sharpie then got my router and a carbide tip bit and removed the material and with a 90 degree die grinder polished with good results checking with feeler gauge and straight edge.
I have a rebuilt motor with pistons that come 0.20 over the top deck and a best gasket with a 0.42 compressed thickness will this work with a Winfield head with no relief cut over the pistons the rods will stretch at high rpm .