1973 Dodge Dart Sport

left heater box outlet..hose..left defroster vent.
right heater box outlet..hose..right defroster vent.

Panel vents are mated to the front of the heater/AC box....no ducting except the 3 vent diffuser.

if the hoses are deteriorated....use DUCT TAPE, and wrap them and reinstall them....or find/buy new duct hoses.