it is already 12v pos. ground, I don't like the Boyer Branson electronic ignition for those but others swear by it. Lucas has made an upgraded breaker plate for those that is well worth the investment. Get rid of the Zener diode and get a Typanium unit to replace it. They make a new version now that looks exactly like the Zener heat sink and mounts in place of it.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!