I have a ford 600 with 12volt conversion. I am looking to go with a petronix electronic ignition but know little about them. I watched a video and learned some. My coil is a 12volt without internal resistor, I have a ballast resistor, negative ground, and plug wires are belden 7mm metallic cable. Has anyone done this and how did it work out?? Tractor is 1956 and an excellent runner but I had a couple issues with spark. Any help would be appreciated. Bob