Replacing the wires on a 6 volt 41'

[Ken T]

I need to replace the wires under the hood and dash. I'm a rookie with 6 volt. I've read and been told that it requires larger gauge wires. I believe that the attached wire diagram is for a 41' truck. Would it hurt it to go with larger wires or does it even matter? I have a new battery. I'm just trying to get it to turn over right now, as there's zero power to anything when hooked up. Any advice would be greatly appreciated.

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