The alt wouldn't have anything to do with it. I can't remember the correct terms here, so bear with me. The reg looks at the voltage from inside the car, which what one of its wires are for, and tells the alt what to do with the other wire. It also looks at under hood temps. If you have bad connections, or corrosion in the connections it could see less than 12 volts, and tell the alt to charge more than needed.
I think you would have better luck getting responses with questions like this if you posted over in the question and answer section, cause a lot of those guys don't bother with restoration stuff.