Built with GM’s engineering expertise, ACDelco and OEM GM parts are factory original equipment replacement parts for your Chevy, Buick, Cadillac, GMC, Saturn, Pontiac, Oldsmobile or Hummer. Every ACDelco and OEM GM part is rigidly held to federal safety and quality standards and is guaranteed by GM Replacement Parts Limited Warranty. You can trust GM Genuine Parts when ordering this Engine Coolant Thermostat Gasket for your 1990 vehicle. GM Parts & Accessories Limited Warranty.