This was my solution.
At one time in my 1954 panel I had both a 12 volt battery and a 6 volt battery.
The 6 volt battery was in the original floor location and the 12 volt battery was mounted on the passenger side fender skirt.
Along with the original 6 volt generator, I mounted a 12 volt alternator with a built in
regulator on the opposite side of the engine, both turned using a single fan belt.
I solid mounted the alternator and used the 6 volt generator belt tension adjustment to tighten-up the fan belt.
The 12 volt battery was used to power a 12 volt high wattage sound system.
The 6 volt battery was used for the truck's original electrical system.
Both batteries shared the same ground.
After playing the sound system for a couple hours, with engine off, the 12 volt battery would drain down dead.
I would kid everyone that we were stranded.
Then I would hop in the truck and start it up with the 6 volt battery.
Adding a 12 volt alternator and battery is a lot easier/cheaper and less invasive than a 6 volt to 12 volt conversion.
Used junkyard 12 volt alternators are a dime a dozen, compare that with what it would cost to convert to 12 volts.
The 12 volt alternator and battery add on system can be easily removed to bring the truck back to its original factory state.
I think I used the the 12 volt battery to jump the 6 volt battery a couple times.
