It became evident early on that converting to a 12 volt Negative Ground electrical system was far better than keeping the original 6 volt positive ground setup. The following are notes of how we did it, not necessarily instructions on how to do it yourself.
1. First thing is to decide if you want to keep the original 6V generator and have it re-wound to 12V neg. ground, or buy a new 12 volt alternator. I discovered that my 1977 Chevy Blazer had the perfect alternator to use for the conversion. It has a built-in regulator, only required two wires to hook up, needed very little modification to the bracketry and was cheap.
2. Next you have to replace everything that was originally 6V with 12V items. This includes things like the ignition coil, headlights, tail lights, parking lights and dash lights. In some cases (like electric gauges or heaters) you might be able to use a voltage reducer to drop it from 12V to 6V.
3. In the case of our truck the whole entire wiring harness was pretty bad, so we replaced every single bit of it. Most of it was the original style cloth covered wire which was dried out and cracked.
Now that the conversion is done, the alternator charges
the battery much faster than the generator, the engine starts more quickly
and any 12 volt accessory can now be added just as easily as a modern vehicle.
At the same time as this conversion was done, I also installed turn signals.