High compression. Black cylinders with highlighted fins. With 0cc piston dome. Compression ratio 11.7:1 for 132" and 12.1:1 for 136" with stock 88cc heads. Compression ratio 11.1:1 for 132" and 11.4:1 for 136" with SE Extreme Port 94cc heads. Largest possible 4.320" bore bolt-in big bore kit. 132" (2162cc) is achieved when used with stock 114" flywheels. 136" (2222cc) is achieved when used with S&S 923270 4-5/8" stroker flywheels. Works with stock crankcases; case boring is not required; stock heads and retains stock engine height. Kit includes a forged 4.320" big bore forged piston kit; 4.320" big bore cylinders; 2 MLS (Multi-Layer-Steel) .040" head gaskets; 2 cylinder base gaskets; 4 cylinder dowels; exhaust gaskets and an S&S cubic inch cam cover badge. Black powder coated finish to match the OEM finish. Note: For the 132" kit S&S measured 135.51HP and 145.83 torque with stock heads; a 550 cam; stock throttle body and a high flow Stealth air cleaner kit. Note: Tuning of fuel injection and ignition may be required. Note: S&S advises 576972 S&S head bolt kit for all big bore applications. Note: 136" is not compatible with OEM 4-5/8" stroke flywheels; must use S&S 923270 4-5/8" stroker flywheels. Note: Not compatible with 107" (4.375" stroke) engines.