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

I understand that the holes in the firewall are different between a/c non a/c cars. I can measure and drill holes.

So, Am I looking for under dash parts from a 66-72 factory A/C car, Or 65-66 car?

I thought the the 65-66 Factory A/C cars used a 4 push button dash controller, while the 67-up used a 5 push button dash controller.

I have a 70 dart with factory A/C that I can use for a reference. This is my first early a-body.