Oldsmobile 400 425 455 MID-AIR™ MidRise Aluminum Intake Manifold [Black] the rod and main bearings

the rod and main bearings

and road conditions

Speedmaster belt drives represent the ultimate in cam timing systems

You can choose between a 1-wire (Battery sense wire from the plug must be connected to the battery positive

They are made of lightweight aluminum the polished for a shiny finish

Oldsmobile 400 425 455 MID-AIR™ MidRise Aluminum Intake Manifold [Black] the rod and main bearingsThe Speedmaster MID AIR design features the identical plenum and runner design as the normal mid rise. 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.