If you do end up adding A/C and coverting to 12-volt, leave the 6-volt horn in. When I converted my 54 GMC, I left all the 6-volt stuff in it just to see what would happen. Light bulbs were fun because the burned really bright for about 5 seconds, but the horn was awesome! You should hear a 6-volt horn when you put 12 volts to it. I will wake up the dead. Here in Arizona we get a lot of snowbirds in the winter that drive extremely slow. In my youth, when I was rude, I rather enjoyed the looks on the faces of the little old ladies that had just been blasted with my 6-volt horn!!