Chevy BBC 454 Oval Port MID-AIR™ MidRise Aluminum Intake Manifold [Black] Suits: 1-149-004 and 1-149-005 Manifolds

Suits: 1-149-004 and 1-149-005 Manifolds

Their dual-idler design has CNC-machined components and they are easy to install

The main difference is that there is an open area under the plenum chamber

Speedmaster brackets are constructed from durable steel

Speedmaster shifters designed to fit most 3 or 4-speed automatic transmissions

Chevy BBC 454 Oval Port MID-AIR™ MidRise Aluminum Intake Manifold [Black] Suits: 1-149-004 and 1-149-005 ManifoldsThe 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.