Where does the red wire go?

It's a little more complicated than this if you have the later dual field connection alternator. One field terminal is hot as soon as the key is turned on and the other one is switched to ground through the regulator. They won't matter if the engine is running or not. The best way is to route power through a switch that turns on when oil pressure comes up. Read Docvettes reply on the hotrodders.com link previously posted.