Proflow Intake Manifold, MaxJr. Single Plane, Aluminium, Oval Port, For Chevrolet, Big Block, Each - PFEM2902Part Number: PFEM2902 Proflows single plane Max Jr intake manifolds are very versatile and can be used for both drag racing and street applications. This manifold design features extended tapered runners and smaller plenum chambers tuned for maximum performance between 3000 to 7500 RPM. They have provision for nitrous bosses to be tapped and are available in natural and black powder coated cast aluminium finishes.