If you aren't going to run anything more than a heater and a cigar lighter, a one wire alternator will work fine. A one wire alternator won't energize and create voltage until its preset RPM is exceeded. Goose the gas one time and it will kick in and charge the battery.
You won't need your voltage regulator (rectangle can), as the one wire alternator has an internal voltage regulator.
Your gas gauge will likely need some inline resistance going to the positive terminal of that gauge to read accurately. You can use a Runtz resister or a miniature 12 volt bulb. A simple pigtail type light fixture will do the job.
You will need to change all of your light bulbs to 12 volt bulbs.
Your six volt starter will turn the engine over twice as fast as it did on six volts. If your six volt starter is in good shape, you will have no problems.
Carl
