OLDSMOBILE HARMONIC BALANCER BOLT HD 307,330,350,403,400,425,455

THIS IS ARE NEW 12 PT STOCK SIZE AN LENGTH GRADE 9 HARMONIC BALANCER BOLT. THESE BOLTS ARE AMERICAN MADE WITH A 3/8 LAZER CUT STEEL PLATE WASHER . THIS BOLT IS STRONGER THEN ARP. WILL FIT 1964 TO 1987 307,330,350,403 SMALL BLOCK AND 400,425,455 BIG BLOCK. IT HAS A 3/4 12 PT HEAD SOCKET. SO NOMORE HAVING TO GO AND BUY A SPECIAL SOCKET .