This 100 mm diameter idler pulley can be used to correct belt length when changing supercharger pulleys or harmonic balancer sizes on the C6 ZR1 LS9, Cadillac CTS-V or Camaro ZL1 supercharged engine. This idler can also be used for many other supercharged engine applications.

Lingenfelter 100 mm Diameter Idler Pulley Kit