[TheMonkey]

i recently went through this several weeks ago. carb is a newly rebuilt edelbrock. it was an issue of no gas in the fuel line. it would do a tiny cough, then had to let the pump send up fresh fuel while cranking. this was after every overnight setting, but wouldn't do it if i parked the car the night before when motor was cool. then... next morning it would be fine. only when i parked the car with hot motor.

turned out it needed a simple tune up. set dwell, timing, and new points. it fixed it, and i have not had the problem again.

i suspect that the motor was running too hot and burning off the fuel after parking a hot motor. some folks suggested a phelonic spacer to get the carb away from the heat.