Designed specifically for GM 4.8/5.3/6.0L cathedral port cylinder head-equipped truck engines and cathedral port LS1, -2, -6 applications where hood clearance is not a concern, the FAST™ LSXRT™ 102 Millimeter Intake Manifold follows the path chartered by the original FAST™ LSX™ Gen III Intake by featuring a modular design that allows for easy porting and disassembly and a runner design that yields an incredible 25 peak Horsepower gain over the stock intake, on a stock 6.0L engine with a Big Mouth 102 Millimeter Throttle Body™. Extensive testing led to a runner design that is longer and less restrictive and gives the user the ability to remove individual runners from the manifold for modification. The LSXRT™ is constructed from a proprietary precision injection molded polymer which offers many benefits, including lighter weight, greater strength and lower heat soak propensity.