OER Parts offers a wide selection of Heater Parts for your 1975 Buick Century. OER Parts offers 1975 Buick Century Blower Motor, 1975 Buick Century Heater Box, 1975 Buick Century Heater Control Valves, 1975 Buick Century Heater Cores. 1975 Buick Century Hoses and Parts, 1975 Buick Century Vent and Duct Parts.