OER Parts offers a wide selection of Air Conditioning and Heater Parts for your 1974 Plymouth Barracuda. OER Parts offers 1974 Plymouth Barracuda Air Conditioning and Heater Control Panels, 1974 Plymouth Barracuda Air Conditioning and Heater Knobs, 1974 Plymouth Barracuda Air Conditioning and Heater Levers and Cables, 1974 Plymouth Barracuda Air Conditioning and Heater Relays, 1974 Plymouth Barracuda Air Conditioning and Heater Switches.