You will need a generator from a '56 to '64 Ford car or F-100. Then you'll need to drill a hole in the side on the new generator to match the dowel pin in the bracket where the 6 volt generator was.The voltage regulator from the same family of Fords the 12 volt generator fits will bolt directly to your firewall.Be sure to get a 30 amp generator/voltage regulator as they are more readily availible. I know some people have used GM style one wire alternators when converting, but this setup will look more like it belongs there in My opinion.Next,you will need a 12 volt solinoid with an insulated base.This should connect with your starter button the same as the 6 volt one did. You'll need to change your coil to a 12 volt coil with a built in ballast resistor.This will keep your points from burning.The other thing you'll need to do is put a resistor in the common wire feeding your gauges.This way you can still use all the 6 volt sending units.The ammeter is an induction type with a wire that runs through a loop. You will need to run that wire back through in the opposite direction so the polarity will be correct for 12 volt negitive ground.You can leave the 6 volt starter in place because for no longer than it takes to start your truck it will last a long time.Mine has lasted 20 years.Also, when your engine is tuned up properly, just a quick bump or the starter and it will be running!The last things you'll need to do is to change all your bulbs and turn signal flasher to 12 volt and get a 12 volt heater motor. Leverett Fernald
I have a question as I was considering changing my '49 to 12V Neg ground...
Wouldn't you have to re-connect each gauge wire on the opposite terminal to reverse the polarity of each gauge as you mentioned with the amp gauge?
I used a 12-6 volt ignition resistor for the gage cluster on my trucks. I do not know the value. Sorry it has taken so long to respond, but I had a setting problem with my computer and just got it repaired today. Leverett Fernald