Need some advice on this. ATI lists #917327 as being correct application for 94-96 Impala LT1 motors. However I do know that the Hubs for the 94/95 motors are a different length (longer) than the 96. The hub on the ATI Damper also has provision for a Key and the 96 doesn't use a key. Do I install the hub W/O the key? My question is... How can this ONE hub fit both 94/95 and 96? Am I missing something here?