The Edelbrock E-Force Supercharger Stage 1 Street system for 2003-06 Silverado and Sierra 1500 and 2007 Sierra Classic increases the performance of your 6.0L Gen III engine to 348 horsepower and 381 ft/lbs. of torque at the rear wheels. The Edelbrock Supercharger also works with the 4.8L & 5.3L Gen III engines, HP & Torque numbers will vary.