Based on performer RPM-series with unique air gap. Air gap cooler and denser mixture for more power. Designed for 1500 to 6500 RPM. Dual-plane high-rise intake. For square bore carburetors only. For street and high performance use. Available in cast, polished or endurashine finish. Product Features:Based on Performer RPM-Series with Unique Air GapAir Gap Cooler and Denser Mixture for More PowerDesigned for 1500 to 6500 RPM Street-Driven PowerDual-Plane High-Rise IntakeFor Square Bore Carburetors Only