OER Parts offers a wide selection of Cooling System Components for your 1966 GMC Truck. OER Parts offers 1966 GMC Truck Radiators, 1966 GMC Truck OE Radiators, 1966 GMC Truck OE Style 2 Row Radiators, 1966 GMC Truck OE Style 3 Row Radiators, 1966 GMC Truck OE Style 4 Row Radiators, and 1966 GMC Truck Copper / Brass Radiators.