Re: 351c odd problem. Engine only starts when key goes back from "start" to "run"
Bump, a friend's F-150 351c had this problem, too.
The ignition was unfamiliar to me, had a mass of wires I couldn't figure out. So we ran a wire from the battery (IIRC) to the coil, through a $3 pressure switch on the dash. You'd have to push the button to get power to the coil when starting but it worked and we could move on to other problems.
When you're going through hell, keep going.
Putts drives a 1965 Galaxie. Rebuilt 390, 4100 on a Performer, MX, AC, PS, PB w Scarebird front discs on Cragar 17" S/S.