Heater Box

There is a difference between package tray and glove box heater box front housing.

Package Tray Heater Front Cover

Glove Box Heater Front Cover

The fresh air vent is also different between the package tray and glove box models. The cable attaches on the left-side of the 70-75 vent and on the right-side on the '76-'77 models.

Package Tray and Glove Box Fresh Air Vent

'73-'75 and '76-'77 Fresh Air Vent

Non-AC Defrost Duct on Top - AC Defrost Duct on Bottom

The AC box was changed to fit a different shape evaporator coil. The early evaporator is made from copper/brass and later evaporators are aluminum.

'70-'71 and '72-'77 Evaporator Coil