[alanwoodieman]

you will need to change the voltage going to the gauges, use a runtz resistor on each gauge -oil pressure, water temp and gas gauge- the volt gauge that is on deluxe cars is a bit different follow 19fordy advice. when you go from six to twelve volts you halve the amperage so the wiring is not a problem. I would install a volt meter in some out of the place so you will really know how much voltage you have and also will let you see if the alternator is working (14 volts) when charging