Chevy BBC 454 Oval Port MID-AIR™ MidRise Aluminum Intake Manifold [Black] These Speedmaster Fuel Rails feature

These Speedmaster Fuel Rails feature a larger internal diameter that dampens the pulses and provides increased fuel volume

They include all hardware for quick and easy installation

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

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

Speedmaster billet aluminum spacers provide the benefits of an open carburetor spacer

Chevy BBC 454 Oval Port MID-AIR™ MidRise Aluminum Intake Manifold [Black] These Speedmaster Fuel Rails featureThe 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.