Allows for easy start by initially reducing crank compression, but once the engine starts and rpm increases, the compression release lobe is centrifugally retracted and the engine runs normally, with full compression, and without any loss in performanceDesigned as bolt-in cams for 103'' engine with stock 9.7:1 compression ratio up to 10.5:1 compression ratioPower in the high rpm range, 3000 rpm - 6000 rpm Includes camshafts, gearcover gasket, bearings, retaining ring, o-ring, threat lock and instructions Made in the USAInstaller must check coil bind, valve-to-valve clearance and valve-to-piston clearance.Works well with stock, unported heads, but is great for S&S CNC ported heads.Not for models with OEM compression releases.