hey guys i want to redo the wireing on my 1940 plymouth just because its pretty torn up from just being old, also the owner before me started replacing all the wires but i dont like how he was doing it and there are only a handfull of wires in the whole car so its not that bad to just switch them out. Its still a 6 volt positive ground system, but at some point i want to change it to a 12 volt neg ground. We wanna get it running as is while we collect some parts but i was wondering if i rewire it now do i need to do it again to switch it to 12 volt or will i just need to replace everything the wires connect, light, gauges, etc.. Also if i want to one have to rewire it once should i use a slighter thicker gauge or should i just stick with whats there. Thanks guys.