Built for high-performance street Pontiac V8 engines, this MidRise Air intake manifold pairs a proven dual-plane plenum and runner layout with an open air-gap base. Separating the plenum from the hot engine valley lets outside air circulate under the runners, so the incoming air/fuel charge stays cooler and denser for added torque and horsepower across a broad street-friendly RPM band. The included adapter plate lets you run either a square bore or spread bore four-barrel carburetor.

Speedmaster 1-147-073 Features:

• Fits Pontiac 326, 350, 389, 400, 428 and 455 V8 engines
• Stock/OEM standard deck block style
• Dual-plane design with air-gap plenum for a cooler intake charge
• Basic operating range: 1,500-7,500 RPM
• Intake manifold height: 6.500 in.
• Single carburetor mount; works with square bore and spread bore carburetors
• Includes carburetor base plate gasket and square to spread bore adapter plate
• Aluminum construction with satin finish
• Non-EGR
• Sold individually