55 massey harris 6v to 12v conversion

looking at converting my 55 to a 12volt system, i have a prety good idea on what can stay & what needs to be switched out, but before i start wrenching i thought it wouldn't hurt to throw the topic out to you guys if you've done it on your 55 what you were able to reuse from a 6v system and what needed to go. thanks

I changed my WD45 Allis a few years ago. I used a delco alt. One wire at first, I didn't like it, had to rev it up almost wide open to start charging. Changed to a two wire, ran the energizing wire to the ign switch. Alt worked fine but tractor wouldn't shut off.(Alt kept putting juice to the coil) If you killed it, it wouldn't run the batt down. Went to radio shack and bought a pack of diodes.(just lets juice go one way). put one in alt wire to switch. Also reverse wires on coil. when you go to neg ground. I am still using 6 volt coil, I thought it would burn up. Starter will be fine.

I'm sure your 55 is pos ground so change the wires on the back of the amp gauge when you go to neg ground so it doesn't read backwards. I have done 30's and 44's and added a starter solenoid for the starter, just used the original button to energize the solenoid. Instead of using a resistor on the original coil, replace it with a 12 volt resistor coil. Get one listed for a 555. They were 12 volt from the factory. If you use the original 6 volt coil without a resistor it will run but will fry the points in time. Use the same points and cond. The starter will work just fine but will spin fast, it will get the drive in time. My 30's will break a drive about every two years. The 44's will break or wind the drive spring tight after a while, so I have started using a 12 volt starter from a 444 which was 12 volt from the factory. You could use a 555 starter. Either use a one wire alternator or use a conventional alt with a diode so it will turn off with the key. If you don't feed it with a diode the alt will feed back to the coil and the engine won't stop. And change the sealed beams. If your 6 volt system is in good shape you could just go to a 8 volt battery, the 6 volt generator should keep it charged up, that works also.