GM Performance parts are sold without a warranty.
Parts thought to be defective upon initial installation can be returned for inspection and will be handled case-by-case. GM Performance transmissions, short blocks, and components are covered under the provisions of the GM Dealer Service Parts and Accessories Warranty for 12 months from the date of original sale or 12,000 miles, whichever comes first. GM Performance crate engines are covered under the provisions of the GM Dealer Service Parts and Accessories Warranty for 24 months from the original sale or 50,000 miles, whichever comes first. This excludes engines, transmissions, and components that are used in racing, competition, marine, motorcycle, or other non-vehicle usage. This also includes engines, transmissions, or components that fail due to alteration or improper use. GM Goodwrench engines installed as direct replacements in a car or light truck application are warrantied for 36 months or 100,000 miles from the time of purchase, whichever comes first. This warranty is the same regardless of who installed the engine. GM Goodwrench engines used in medium-duty truck applications (40 through 70 Series) are warrantied for 18 months with unlimited miles if installed by the dealership, or 12 months with unlimited miles if installed elsewhere. This warranty does not cover vehicles registered and normally operated outside of the United States.