New INNOVATORS WEST 10% overdrive IW crank balancer kit for 09-13 Supercharged Corvette ZR1 6.2 LS9
SFI 18.1 Harmonic Damper kit 870 for GM 2009-13 ZR1 (LS9) Corvette – w/ Crank Bolt. 11 Rib & 10% Overdrive Pulley. it adds 2lbs of boost
Exceeds SFI 18.1 standards and is marked on front with SFI Sticker, and on the rear with SFI number stamped into unit.
IW balancer assembly 870