Heater Box Assembly for 1965-1966 Mustangs with a 3-speed heater motor.
The heater box assembly consists of the front and rear casings with doors. This is a factory type fiberglass two piece heater box/heater core casing. The heater box is a pre-assembled unit which includes the gasket and all seals. The heater plenum attaches to this assembly and directs warm air to the car.