Stage 1 means this kit arrives with calibration included, so unlike the Pro-Tuner systems it is meant to be installed and driven rather than handed straight to a tuner. The intercooler sits in the supercharger housing to keep charge temperatures down, which is what protects a truck engine that spends real time under load towing or hauling.

Edelbrock 1577 E-Force Supercharger Specifications:

• Fits 2003-2007 Chevrolet Silverado and GMC Sierra with 4.8L, 5.3L or 6.0L engines.
• Cast aluminum housing, black powder coated, with an intercooled center section.
• Calibration included along with 42 lb/hr injectors and an air filter.
• Gaskets, hoses and mounting hardware included. Requires a 7.5 in. harmonic balancer.
• Confirm your model year by VIN.