Goodmark Heater Plenums

Goodmark heater plenums are OE replacements made of injection-molded high-temp ABS plastic. They fit just like the original for improved durability over the factory cardboard plenum. These quality plenums attach to the heater box, and allow the diversion of hot air to the ducts that travel to the dash and defrost the vehicle's windshield. They include flapper door, cable clamp and screw already attached, and the inner door already has closed-cell foam bumpers installed. If you're worried about the heat or defrost in your 1965-68 Mustang or Cougar without A/C, make an upgrade with heater plenums from Goodmark.