Speedmaster®
Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Satin]
![Speedmaster® 1-147-073 Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Satin]](https://product-arena.s3.us-west-1.amazonaws.com/Speedmaster/1-147%20Intake%20Manifolds%2C%20Carbureted/1-147-073/1-147-073.jpg?resizeid=225&resizeh=50&resizew=50)
![Speedmaster® 1-147-073 Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Satin]](https://product-arena.s3.us-west-1.amazonaws.com/Speedmaster/1-147%20Intake%20Manifolds%2C%20Carbureted/1-147-073/1-147-073_A.jpg?resizeid=225&resizeh=50&resizew=50)
![Speedmaster® 1-147-073 Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Satin]](https://product-arena.s3.us-west-1.amazonaws.com/Speedmaster/1-147%20Intake%20Manifolds%2C%20Carbureted/1-147-073/1-147-073_B.jpg?resizeid=225&resizeh=50&resizew=50)
![Speedmaster® 1-147-073 Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Satin]](https://product-arena.s3.us-west-1.amazonaws.com/Speedmaster/1-147%20Intake%20Manifolds%2C%20Carbureted/1-147-073/1-147-073_C.jpg?resizeid=225&resizeh=50&resizew=50)
Product Information
Overview
This is an outstanding manifold for high performance street Pontiac engines. Unlike similar competitive manifolds, the MidRise Air from Speedmaster allows unlimited ambient air-flow under the plenum and around the runners which helps create a cooler incoming air/fuel charge which produces additional power..
Specs
| Brand: | Speedmaster |
| Part Number: | 1-147-073 |
| 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: | Satin |
| 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. |
Description
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.
Warranty Information
12-Month Limited Worldwide Warranty
Prop 65 Warning
This product may contain chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm.
Installation Guide
Our AI assistant generates a step-by-step guide for this product — covering installation, maintenance, and troubleshooting.
This AI-generated guide is for general reference only and does not constitute official Speedmaster product documentation. Always verify fitment, torque specifications, and safety requirements before installation.