I have a 1965 scout 80. Right now it has a single fuel tank. I am planning on installing dual fuel tanks. My question is how does the fuel gauge work with both tanks? Is there a switch that changes from left to right tanks? I know there is a switchover valve for switching the fuel from one tank to another. But what about the fuel sending unit readings? Any help in this matter would be grateful. A wiring diagram would be nice too.