Speedmaster®
Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Black]
![Speedmaster® 1-147-075 Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Black]](https://product-arena.s3-us-west-1.amazonaws.com/Speedmaster/1-147%20Intake%20Manifolds%2C%20Carbureted/1-147-075/1-147-075.jpg?resizeid=224&resizeh=600&resizew=600)
![Speedmaster® 1-147-075 Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Black]](https://product-arena.s3-us-west-1.amazonaws.com/Speedmaster/1-147%20Intake%20Manifolds%2C%20Carbureted/1-147-075/1-147-075_A.jpg?resizeid=224&resizeh=600&resizew=600)
![Speedmaster® 1-147-075 Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Black]](https://product-arena.s3-us-west-1.amazonaws.com/Speedmaster/1-147%20Intake%20Manifolds%2C%20Carbureted/1-147-075/1-147-075_B.jpg?resizeid=224&resizeh=600&resizew=600)
![Speedmaster® 1-147-075 Pontiac 326 350 389 400 428 455 MID-AIR™ MidRise Aluminum Intake Manifold [Black]](https://product-arena.s3-us-west-1.amazonaws.com/Speedmaster/1-147%20Intake%20Manifolds%2C%20Carbureted/1-147-075/1-147-075_C.jpg?resizeid=224&resizeh=600&resizew=600)
Product Information
Overview
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.
Specs
| Brand: | Speedmaster |
| Part Number: | 1-147-075 |
| 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: | 1,500-6,500 |
| Intake Manifold Height: | 6.50 |
| Intake Material: | Aluminum |
| Intake Finish: | Black |
| EGR: | No |
| Quantity: | Sold individually. |
Description
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.