Oldsmobile 400 425 455 MID-AIR™ MidRise Aluminum Intake Manifold [Black] The ends are factory-crimped to

The ends are factory-crimped to eliminate leakage

Due to the large-diameter 13 in

Speedmaster cylinder head fasteners are made from aircraft quality 8740 high tensile strength chromoly steel and cold-forged to ensure molecular integrity

Each kit comes with high-torque motor

Its unique construction features an aluminum core with an outer silicone coating

Oldsmobile 400 425 455 MID-AIR™ MidRise Aluminum Intake Manifold [Black] The ends are factory-crimped toThe 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.