Riva's new XX-Charger for 300 engines delivers up to 17.5 psi of boost pressure producing arm wrenching acceleration and increased top speed. High performance billet impeller & 3mm spacer increase horsepower through superior impeller blade design and larger interior housing volume. Lightweight billet impeller features a sophisticated blade design that is precision balanced to deliver smooth operation. Impeller is 22 grams lighter than stock providing improved reliability of clutch and bearings. Spacer & impeller install quickly and easily onto stock supercharger base plate. IJSBA Limited Class legal. Requires modifications to fuel delivery system to match increased horsepower. Includes detailed installation instructions.