A couple more wiring questions

Reuse the a/c underdash harness. You said your missing the connection to plug into your a/c controls and missing the plug that leads to your blower motor resistor. Either the manufacturer left it out on accident or your supposed to buy an A/C harness/reuse your original.
I wired up a friends 72 torino a few years back. We had to reuse the A/C, wiper, and voltage regulator harnesses.