GM LS (58X) Single Chain 9 Keyway Adjustable Billet Timing Set (Single-Bolt Gear, 4 Pole Reluctor)Induction hardened and precision machined, Steel billet Gears for bullet proof durabilityFeatures 9 keyway crank sprocket for 2-degree incremental adjustability, 8-degree maximum advance/retardPrestretched, heat-treated double Roller chain with heavy-duty large pin designIdeal for all street performance and Race Applications