What are the differences between 65-66 and 67-73 Factory A/C

OK here you go!

First pic is of a donor firewall for location of various holes. I will remove the heater blower area when I convert my 65 Barracuda to AC.

The 2nd pic is of the firewall in my 65 Dart after I added the blower area from another donor and added all the various holes for everything. I've still got to change the vertical firewall harness connector to horizontal so it will clear the AC box. The heater and AC box fit perfectly.

3rd pic shows the 5 button bezels for a 65 Dart (top one) and a 65 Valiant/Barracuda.

Hope all this helps