Recently did mine in a 65 A body Valiant. Not AC, but should be close.
Drain radiator coolant
Disconnect heater hose clamps and hoses from firewall area
Use a plastic tube and syphon as much coolant as possible from the radiator core
Remove small metal cover from firewall side which holds the heater line hose fitting in place
From the inside remove glove box cover, remove glove box. Probably 2 small screws on the side holding it in place
There are 3 cables that control air flow , temp and defrost. they are top of the heater box inside the car. I suggest labelling them so you know which one goes where on reassembly
They have a small metal clip on top of them where they hook onto the control shaft.. they need to be gently pushed up and off. Don't loose them.
Each of the cables has a clip to hold the cable end in place. this clip is secured with a small screw into the bracket.. Once the screw is out, use a small screwdriver to pop the clip off of the metal tang, from the bottom or side.
remove the 3 cables from the heater box and secure them out of the way.
remove the heater air tubes from the heater box, secure out of the way.
At the bottom right corner of the heater box under the vent door, is a small bolt. It is connected to a shaft, which goes up inside the vent and hooks on top of the air hole.. Reach up in there and see how it is set up. As you unscrew that bolt.. the rod will come free and you can un hook from the inside of the heater box vent and remove.
Make sure you hold that shaft with pliers or something as the bottom has a metal L shaped tang which could spin if the bolt is rusted in there and could damage your heater core.
Un hook electrical power at the heater resistor. It is right on top of the heater box.
Disconnect the ground wire.. On mine it was screwed to the body behind the kick panel on the passenger side.
You are almost there
Go back under the hood.. There are 4 nuts holding the heater box fan motor in place. remove them and gently push the heater motor to the inside. There is a metal ring, and a rubber washer behind it.
Now go back inside and gently work the whole box inwards until it basically falls toward you.
You did get as much of the coolant out as possible right...? Otherwise this is where you get antifreeze on your carpets.
Watch out for 4 small metal spacers which seem to get hooked out and fall behind the insulation.. They go on the blower mounting studs to seperate the box from the firewall. They are about 3/4 inch long.
That should be it
On mine I put in a new blower motor, then wired in a 4 speed resistor, new 4 speed fan and on and off switch from a different make to provide a few different levels of fan speed. If you want details let me know
If you need some pictures , log into Classic Auto air and download their installation manual for the late 60 a body mopar install.. It shows lots of pictures as you take the original unit out.
Happy Holidays
