[JSeery]

Is there a reason you are wanting to switch to a 12v system? If you are keeping the car mostly original that seems like a lot of effort for little or no gain. The reason most switch to 12v is to accommodate modern electronics, such as a radio, etc. The switch will require a new 12v generator or alternator, bulbs, horns (if you want them to work correctly, voltage reducers for the gauges, new starter solenoid and most likely a new starter.