OER Parts offers a wide selection of Body Panels for your 1989 GMC Truck. OER Parts offers 1989 GMC Truck Cowl Panels, 1989 GMC Truck Cowl Drain Flap, 1989 GMC Truck Side Cowl Panel, 1989 GMC Truck Cowl Panel Plugs , 1989 GMC Truck Cowl Drain Hose, and 1989 GMC Truck Cowl Gasket.