Original AC heater boxes arnt easy to find, so it was worth trying to restore it.
I ended up getting a new heater core made and the original evaporator tested ok.
The WCC Videos were also very helpful (Thanks Don).
I was missing the Plenum chamber and discovered the Mustang one was quite different.
Next is testing the blower motor / wheel next while Im waiting for some parts to arrive.
This job was a bit daunting (because id never done it before) but I took a lot of photos pulling things apart. It also had to be done as the next step is starting to put the dash etc back in.
Thanks Al, mine too! 
That’s looking awesome!
Here’s a pic of the firewall side of the heater box & what it should look like. This is a repro but it should give you an idea.
Basically if you have this seal, it will give you a guide as to how to shape that opening.
You can strengthen them up with a layer of fibreglass weave (not chop) over the outside
These look a bit manky but with a sand and satin black paint they come up OK
BF Falcon 4 speed fan
Thanks Andrew, thanks for the pic. that’s one of the parts Ive ordered so it will help to get the shape right.
I like that Falcon fan Leon, probably heaps more efficient as well.
Nice work!
Wow, that worked out well! Great job!
Ive bought some Dynamat and getting ready to put the dash back in.
Im just missing a couple of air con pieces if anyone can help.
If anyone can help with the wire frame for the plenum chamber or the right plastic air duct that would be great.
One of my dream Cougars - looking fantastic!
- Phillip
That is looking good!
Big Thanks to Randy for looking after the parts.
I can move forward on the dash / interior now.
Looking good!!!
I hear that! Hope you took a bunch of “before” pics, LOL! If not, I’m sure we can help. I know I have some pics from when I pulled my dash pad.
Hi Guys, my dash has a hole in the same place as the circled item.
Can anyone tell me what this is or what its for?
Thanks