I'm looing for one of these to install on a GM 105 amp alternator, or, just buy an alternator that comes stock with a clutch-serpentine pulley on it.

They are designed to allow the alt to free wheel when an engine is decelerating, and to remove the torsional forces on the crank vibration damper by this clutching action.

Anyone know where I can get one? And the special tool required to install one?