Intake Manifold Assembly – GM (12631021)

Intake Manifold Assembly is the intake manifold that feeds air into the cylinder heads. Gasket surfaces and injector bore placement are specific to the engine family, and warping at the flange is the usual cause of a lean code.

Replace the Intake Manifold when the flange face is warped, when a runner has cracked, or when an injector bore is damaged. Confirm that the gasket surface is flat, or the replacement will leak the same way.

This Intake Manifold is listed as part 12631021 (Throttle Bodies & Intake). Where a number has been superseded, the current reference is the one that ships, so check any supersession note before ordering.

The stock here is genuine GM, and this Intake Manifold keeps the original engineering number, which matters once a number has been superseded more than once.

This is sold as an assembly; if only one component has failed, confirm whether the single part is available separately.