Holley Avenger Airfoil Kit 120-140 | Talk about a smooth operator, this Holley airfoil kit easily adapts to the stock GM throttle body on Chevrolet 5.7L TPI and LT1 engines used on Camaros and Firebirds. It acts to smooth out and minimize the turbulence of the incoming flow of air into the throttle body. The September, 2002 edition of GM high-tech performance magazine reported a 5.8 horsepower increase after installing this Holley airfoil kit on a stock 1994 Camaro Z28 LT1. Installation is easy; simply snap it into place in the mouth of the throttle body and it's ready to work. Made from space age elastomer, the Holley airfoil will perform effectively and unobtrusively for years.