OER Parts offers a wide selection of Cooling System Components for your 1966 GMC K15/K1500 Pickup. OER Parts offers 1966 GMC K15/K1500 Pickup Radiator Hardware, 1966 GMC K15/K1500 Pickup Petcocks, 1966 GMC K15/K1500 Pickup Radiator Petcocks, 1966 GMC K15/K1500 Pickup Brass Radiator Petcocks, 1966 GMC K15/K1500 Pickup Radiator Drain Petcock with Hose, and 1966 GMC K15/K1500 Pickup Cooling System Zinc Anode.