YEAR                PART NUMBER       ORIGINAL APPLICATION:
1955-57              518114              PRODUCTION, FORGED & BUSHED
1958-62              532294              PRODUCTION FORGED
1959-61              528979              389 SUPERDUTY (FORGED)
1962-63             529238               421 SUPERDUTY (FORGED & HEAT TREATED)
1963                  9772118             421 AFX (MICKEY THOMPSON ALUMINUM)
1963-65             544956               421 HO (FORGED OR CAST)
1963-79             541000               PRODUCTION CAST
1969                 545855                RAM AIR V (FORGED)
1973-74            485225                 455 SUPERDUTY (FORGED)