The Edelbrock Performer Intake Manifold delivers superior performance with square-bore carburetors. Horsepower gains from idle to 5, 500 RPM, when used with Performer Series square-bore or Thunder Series AVS carburetors. Dyno tests show that the power gains an extra 5 horsepower, 9 foot / pounds and torque across the entire RPM range over their own performer manifolds.