Proflow RPM AirMax FE intake manifolds are designed for high-performance street usuage. Their dual-plane constant cross-sectional area design builds low and mid-range acceleration, while optimised runner paths make top-end horsepower. These manifolds have a provision for adding the PCV or breather flange at the rear, and no exhaust crossover passage. Used perfectly with Proflow AirMax Cylinder Aluminium FE Heads.