SLP Performance - 04 GTO Supercharger Package, LS1 GTO 470HP Silver Finish Intercooled SLP's High-Output TVS 1900 Supercharger (Silver Finish) for the 2004 GTO is the same technology offered in the new ZR-1 Corvette. It safely provides 7 PSI of boost, creating stump-pulling torque and neck-breaking acceleration. It increases the power of the stock LS1 5.7L engine (at the flywheel) from 350 HP to 470 HP. This Supercharger Package is emission-legal in all 50 states. E.O. #D-488-6. Includes all necessary installation hardware and instructions. 2004 GTO Supercharger Packages Feature: Fits LS1 V8 engines. Silver Finish for an OEM appearance. Fits under the stock hood without modifications. Increased torque and horsepower from idle to redline providing more power under the curve. Self contained lubrication system that is maintenance-free. Emissions-legal in all 50 states