My truck was 12v when I bought it. Non running converted way back maybe in the 70's. I don't like 6v on anything. I've converted all my old tractors to 12v and personally would never even consider 6v as an option. Thats just me, I know some people want original OEM, but I want reliability, ease of use and parts. I went with Deve's HEI system, and it was not hard to do. I have not run my truck yet as I'm still assembling it, maybe this winter I'll get to the point where I can, by spring drive it out of the garage. So far, I've rebuilt everything on it. I started in Feb 22 and hope to have it all done by spring. My truck will look close to it's original form, I'm not putting a V8 in it. It had a 235 in it, and a sm420 4speed. I added a Gear Venders overdrive so my final ratio will be 3.55 to 1. The rear end is in very good shape, as was the steering and front end. I rebuilt all the brakes, engine, gas tank, cab interior, box, all new glass, gauges, and every body panel.