Part Type: Engine Coolant Thermostat Housing Gasket. 2004 Buick Regal Engine: 3.8L V6;EngineVIN: K; Molded Rubber;. Gasket Material: Molded Rubber. Compatible Years: 2004. Ensure that this part fits your vehicle by entering your vehicle's Year, Make, Model, Trim, and Engine in the Compatibility Table.