GM Genuine Parts Exhaust Manifold (Part Number: 12643496 ) is a genuine OEM exhaust manifold designed to collect exhaust gases from the engine cylinders and direct them away from the combustion chamber. It supports proper exhaust flow and interfaces with the vehicle's exhaust system to help maintain engine performance. Category: Engine Component Parts Function: Channels exhaust gases from the engine to the exhaust system to promote safe and efficient evacuation of combustion byproducts Application note: Referenced for various GM mid-size models (see OEM fitment). Quality: Engineered and tested to GM factory standards for fit and durability Exhaust Manifold