PERFORMER RPM FE (1500-6500 RPM) Designed for high-performance street 390-406-410-427-428 c.i.d. Ford FE V8's with standard 390-428 c.i.d., 427 low/medium-rise or Edelbrock Performer RPM FE heads. The dual-plane constant cross-sectional area design builds low and mid-range acceleration while optimized runner paths make exceptional top-end horsepower. Has provision for adding the PCV or breather flange at rear. No exhaust crossover passage. Also available as a complete manifold and carb kit. * CARB RECOMMENDATIONS: Edelbrock Thunder Series AVS or Performer Series (650-800 cfm) Carburetor. For auto. trans. use our #1483 or #1844. ** Recommended intake gasket: Edelbrock #7224. Manifold height: A-4.89", B-6.04"; Carb pad height: 5.46". Port exit dimensions: 1.16" x 1.97". For the heights of all Edelbrock manifolds, please use the Manifold Reference Dimensions guide.