The AEM Tru-Power Underdrive Pulley Kits are designed to replace the pulleys on both the alternator and power steering pump. AEM has chosen to underdrive the accessories via their pulleys as opposed to the crankshaft pulley because the vibration dampner incorporated into the crankshaft pulley is critical to engine life. The Tru-Power Pulleys are CNC machined from billet 6061 T-6 aluminum and anodized in red, blue, or clear silver. The kits come complete with pulley(s) and belt(s) and a full set of instructions for ease of installation. *When ordering insert "B" for blue, "C" for clear or "R" for red after part number to indicate color desired. **Alternator pulley only.

Unorthodox Racing Ultra Street lightened underdrive pulleys are CNC-machined from lightweight 6061-T6 aluminum billet. Premium 6061-T6 aluminum billet ensures the consistency of the material's strength and balance. Tolerances are held to within .001", and numerous machining steps are used to ensure the lightest possible design. In addition to fit, finish is just as important and each piece is representative of this. Unorthodox Racing pulleys can provide gains of 5 to 12 HP and 4 to 8 ft.-lbs. on normally aspirated engines and 8 to 16 HP and 8 to 18 ft.-lbs. on forced induction engines. *When ordering insert "BLK" for black, "C" for clear "R" for red or "BLU" for blue after part number to indicate color desired.