Fits: 2001 thru 2010 Chevy Silverado/GMC Sierra 2500HD/3500HD LB&/LLY/LBZ/LMM Duramax Diesel Part# CP3-DMX-SS Brand New Pump (No Core Needed) THE MANUFACTURE, SALE, OFFER FOR SALE, OR INSTALLATION OF THIS PRODUCT IS NOT LEGAL IN CALIFORNIA This Brand New LBZ Based S&S Supersport pump is a great semi stock replacement for customers looking to push more fuel and gain horsepower. These Pumps are brand New and no core is needed. The Supersport pump is modified to eliminate the fuel flow restrictions that begin at 3000 RPM on stock CP3's. This pump can also be used in a LML CP3 conversion(tuning may be required). Note: Tuning is REQUIRED if installing on 2001-2005 LB7 and LLY engines. Fitment on LB7's requires you to modify the regulator connectors to make them fit.