If you are going to stick with the 6 volt system, the wiring harness should have the heavier gauge wire.
Off the top of my head I don"t recall what the 6 volt wire gauge is/was.
You could call these guys
http://www.ynzyesterdaysparts.com/catalog/They would know what the original gauge is.
Here is there list of
Chevy Truck Wiring Harnesses Pricey
They also do custom harnesses.
Ask them what it would cost to make you a 1950 (Early)1953* 1/2 ton Vinyl Wire harness.
