The Colt Cams C.1014.S Street/Strip Camshaft is high-performance "drop-in" replacement for your 01-10 GM 6.6L Duramax. Constructed from a brand new billet, this camshaft comes pre-machined with a new keyway and key. This eliminates the weak factory dowel pin which has been known to shear allowing the cam gear to slip, and sometimes even cause catastrophic engine damage. The Street/Strip cam requires no valve relief and drastically improves throttle response, bottom end, mid-range power, spool-up, and overall driveability. Features:Â "Drop-In" Performance Cam Pre-Machined Keyway & KeyÂ Improved Engine PerformanceÂ Â Not available for sale in the state of California Click here to read Emissions Notice.