Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Polished]

Brand:	Speedmaster
Part Number:	1-147-074
Part Type:	Intake Manifold, Carbureted
Product Line:	MidRise Air
Engine Block Style:	Stock/OEM standard deck
Carburetor Quantity:	One
Intake Style:	Dual Plane
Basic Operating RPM Range:	1,500-7,500
Intake Manifold Height:	6.500 in.
Intake Material:	Aluminum
Intake Finish:	Machined Polished
Carburetor Base Plate Gasket Included:	Yes
Square to Spread Bore Adapter Plate Included:	Yes
EGR:	No
Quantity:	Sold individually.
Notes:	Works with spread and square bore carburetors.

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.