1962 Ford Custom 1951 Ford flathead

Engine Mechanical problem
1962 Ford Custom V8 Two Wheel Drive Manual

my car will only run for about 1-3 seconds then shut off.
It ran fine then it sat for a few months. I had both carbs professionally rebuilt, new points, new plugs, new gas, I have spark, my timing is retarded at the moment between 4-6 degrees. It should be running at negative 2 degrees but it doesn't make cense to me that that is what is keeping the car from running. Any help is very much appreciated thanks