Chevy BBC 454 Oval Port LowRise Aluminum Intake Manifold [Black] The outer cases made from

The outer cases made from 8620 Chrome-Nickel-Moly steel and the case hardened for long life and improved strength

Speedmaster CNC ported cylinder heads are machined on dedicated 5-axis CNC machines to ensure accuracy and better flow

One very small

This feature is sometimes called an air gap design

Chevy BBC 454 Oval Port LowRise Aluminum Intake Manifold [Black] The outer cases made fromThe Speedmaster LowRise Manifolds are our lowest profile manifold and is also the only one that is street legal on pollution controlled vehicles. It is set up to accept a spread bore carb but comes with an adapter plate that permits the use of square bore carbs. To remain street legal with a square bore carb, you must use one that is also approved as street legal for your application.