This manifold is the result of over one year of development and testing and has proven to provide significant increases in power. In direct comparison dyno tests against a factory LS6 intake manifold, the Typhoon produced 17.7 more horsepower at 6,200 rpm. It also makes more power and torque at low and mid-range engine speeds than other aftermarket manifolds. This design features a larger plenum volume, which makes the manifold suitable for larger displacement engines. The manifold has nitrous bosses positioned on the port runners. The LS1/LS6 version comes with either an 85 mm inlet or a 96mm inlet. Professional Products offers 80 and 85mm throttle bodies and 96 and 101mm throttle bodies are in development. The 96mm inlet version of this manifold can be used with either the stock 91mm LS2 throttle body or various aftermarket large bore throttle bodies. The manifold kit includes high volume fuel rails with stainless steel mounting brackets, stainless hardware, and a -6 AN stainless braided crossover hose. Additional fittings are also supplied that allows connection to the stock fuel inlet line.