This very trick pulley is machined from billet aluminum & black anodized. It is oversized (5") to reduce the speed of the generator or alternator on high rpm engines preventing over charging the system.
When using this pulley with the original water pump pulley CAM6239, use
GCB10863 fan belt.
When using this pulley with
CAM6408 water pump pulley, use
GCB10900 fan belt.
15mm shaft size,just over 17 inc woodruff key