Harmonic Balancer/Underdrive Pulley, 1997-13 LS1/LS6/LS2/LS3 25% Underdrive

SLP's new 25% underdrive balancer for LS1/LS6/LS2/LS3 Corvette's incorporates a number of high-quality features you won't find on any other aftermarket unit. Chief among them are a pair of extra-tall belt-retention walls that eliminate the belt-slippage issues common to other balancers (see photo). Gains of up to 10 horsepower can be expected. Other unique design strengths include 100% steel construction (other brands use steel and aluminum), integral timing marks, and built-in puller-mounting threads. Includes a new balancer bolt and detailed installation instructions. NOTE: Requires new serpentine belt (Dayco #5060780 or equivalent, not included). FEATURES: * Extra-tall belt-retention "walls"--no more thrown belts! * No aftermarket tensioner required * 100% steel construction * Lighter than the stock balancer * Integral timing marks and puller-mounting threads * Keyed for high-rpm or supercharged applications * Does not cause false knock retard or erratic power-curve dips * Includes a new balancer bolt * SFI Approved