OER Parts offers a wide selection of Heater Parts for your 1973 Buick Century. OER Parts offers 1973 Buick Century Blower Motor, 1973 Buick Century Heater Box, 1973 Buick Century Heater Control Valves, 1973 Buick Century Heater Cores. 1973 Buick Century Hoses and Parts, 1973 Buick Century Vent and Duct Parts.