Howdy! 1978 F-150 with 400M. Engine runs like a champ (when it's running!) Edlebrock carb and manifold, headers. Fresh rebuild with zero issues for about 13000miles/1 year. Everything is tight. Fuel is clean. No fuel delivery issues. Carb is properly adjusted, to include electric choke. Ignition switch NOT loose or any hanging wires.

PROBLEM: After warm-up while driving under normal conditions, engine will die for apparently no reason. All electrical items are still working (lights, radio, etc). Pull over, put in park, immediately starts right up and runs. Will continue to do it all the way home. Daughters daily driver so this is unacceptable.

Sat in the garage with engine idling after warmup, wiggled ignition switch to no effect. Disconnected duraspark, engine dies. Reconnect, immediate start-up.

Any assistance would be greatly appreciated.