if your block is at 4.030 to 4.060 your head gasket should be abit bigger so the fire ring is not in the bore so 4.125 should work fine but the .039 4.125 is 8.7 cc and the 4.185 with steam holes done is 10.2 cc the steel shim is 4.150 and 5.4cc all will work with steam holes added