I have a good generator that came out of a '46 Chevy 3100. Unfortunately it's on the opposite coast from you...
I think it may have been rebuilt, but not sure. It seems to have a new chrome strap on it which is why I believe it's rebuilt.
It was working in my truck before I converted it to 12v.
Not sure if it will fit in a Med./Lg. flat rate box, I can check if you're interested in it. You can have it, just pay for postage.
As far as conversion, if you decide to go with an alternator and convert to 12v, figure about $50-$100 for an alternator, and you can get a bracket to mount it for about $20, a coil is about $25. You need to keep your flywheel with your starter though, the 6v and 12v are different (I think 6v is 139 tooth and the 12v is 153 tooth. The pinions on the starter are also different, the intention was so that the starters were not mismatched. You can use your 6v starter with a 12v battery, but not the other way. You also need to replace your bulbs and add a resister on the fuel gauge. Oh, and I think I had to get some type of harness for the alternator electrical so I didn't have to hack up the wiring. I got all the stuff from Jim Carter.
IMO it really depends on what you plan for your truck. If you want to have a radio and/or navigation system, or charger for your cell phone, that stuff if better suited for 12v, it will be able to handle it better. With 6 volt you can still have an inverter to convert 6v to 12v, that's another solution to get a 12v cigarette plug. Kind of funny, smoking is taboo, but we use those plugs a lot, heh? (I know I do! LOL)
