Re: 12 volt conversion
I recently converted my Ford 640 to 12v and electronic ignition. Boy she fires off instantly now.
My 12v electronice ignition: http://www.tractorpartsinc.com/ford_tractor_electronic_ignition_conversion_kit_5502_prd1.htm
You may need a new coil. http://www.tractorpartsinc.com/high_performance_heavy_duty_ehdc_2661_prd1.htm
I have been told you can use a coil from a car/truck as long as they are 12v. I did buy the high energy coil. Remember to switch your ground to 12v neg.