OER Parts offers a wide selection of Cooling System Components for your 1966 GMC 1000. OER Parts offers 1966 GMC 1000 Water Pumps, 1966 GMC 1000 Chrome and Polished Pumps, 1966 GMC 1000 Electric Water Pumps, 1966 GMC 1000 High Volume Pumps, 1966 GMC 1000 OE Style Water Pumps, 1966 GMC 1000 Reverse Rotation Water Pumps, and 1966 GMC 1000 Water Pump Pulleys.