Much like any accessory, spinning the alternator at a slower speed reduces the amount of power required to drive it at any given rpm. Conversely, spinning the alternator faster results in more voltage output which is ideal for vehicles with performance stereos. We got both crowds covered! Purchase the WBS 10% underdrive pulley for an increase in engine power and purchase the WBS 10% overdrive pulley for an increase in electrical power.

As always W Body Store pullies are made from aluminum and are generally the lightest on the market.

Please note: Pullies intended for use only on 97' - 03' W Bodies and 04+ utilizing the series II engine