I HAVE THIS NICE PAIR OF 6272990 CHEVY RECTANGULAR HEADS WITH STUDS AND GUID PLATES,NEW TEFLON SEALS.I BOUGHT THEM FOR A MOTOR I WAS GONNE BUILD,BUT,AM GOING WITH A FORD 460 NOW INSTEAD.THESE WERE PULLED OFF OF A RUNNING BIG BLOCK BOAT MOTOR WITH LOW HOURS,AND HAVE STAINLESS VALVES INSTALLED ,I...