to A/C or not to A/C?

I have a 68 Dart GT. It is an air car. Most of the parts were removed by a previous owner. I am in the process of finding the parts needed to make it an air car again. Why? Because air in these cars is rare. I like the comfort of air on hot days. Last but not least. How much hp are you going to lose if the air is off? Not enough to worry about in my opinion. Put the parts back in the car and ride in comfort as well as in style.
Frank