SLP's 25% underdrive pulley balancer for GTOs incorporate 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 endemic to other GTO balancers. Other unique underdrive pulley design strengths include 100% steel contruction (other brands use steel and aluminum), integral timing marks, and built-in puller-mounting threads. SLP Harmonic Balancer/Underdrive Pulleys include a new balancer bolt and detailed installation instructions.
Features:Extra-tall belt-retention walls = no more thrown beltsNo aftermarket tensioner required100% steel constructionLighter than the stock balancerIntegral timing marks and puller-mounting threadsKeyed for high-RPM or supercharged applicationsDoes not cause false knock, retard or erratic power-curve dipsGM balancers include a new balancer bolt