The ammeter doesn't care if it's 6V or 12V, the water temp and oil pressure guages are mechanical, not electrical. That leaves the fuel guage. There are some on here who have run their stock fuel guages on 12V for years with no problems. Others opt for a voltage dropping resistor that can be purchased from many of the parts vendors. Also, the bulbs that light the cluster need to be changed to 12V. Hope this helps.
