General Motors Corp. will pour $63 million into its Saginaw, MI, casting plant to produce cylinder heads for the auto maker’s high-feature 3.6L V-6 engines.

The investment will go to fund new semi-permanent mold processing equipment that will be used to manufacture the castings. Some of the money will be spent on additional plant renovation.

Construction will get under way in spring 2009 and be completed in January 2011, GM says. The investment means about 130 hourly jobs will be retained at the plant.

GM says the semi-permanent mold process is considered to be the most reliable for casting cylinder heads. It uses a water-cooling process to produce a high-integrity microstructure that ensures increased material strength.

The auto maker currently offers the 3.6L engine in its new line of cross/utility vehicles, the Saturn Outlook, GMC Acadia and Buick Enclave.