1979-1990 GMC C5000 5.7L V8. 1979-1987 GMC C5000 4.8L 6 Cyl. Notes: Engine Coolant Outlet Gasket -- Use: Water Outlet; Composite Material; 1-13/16in I.D. Validated for fit, form, and function. Ensure Proper FitTo confirm that this part fits your vehicle, enter your vehicle's Year, Make, Model, Trim and Engine in the Compatibility Table.