Speedmaster 1-147-020 Compatible with Chevy BBC 454 Oval Port MidRise Air Aluminum Intake Manifold [Polished]

The Speedmaster MidRise Air design features the identical plenum and runner design as the normal MidRise. The main difference is that there is an open area under the plenum chamber. This feature is sometimes called an air gap design. The air flowing under the plenum provides a cooler charge for the incoming air with less heat transfer from the engine. This cooler air charge provides additional power and torque.