The carbs are rather basic; mine does that. I retard the timing full, then cheat and give it a slight advance. Throttle to the floor as with any flooded carb, idle mixture 1/4 turn open. It should start if this is the only time you have trouble getting it going. I plan to build a carb myself and see if I can manage to improve this.
Actually, my '77 LTD does that, to a lesser extent, but also carbureted. Starting cold it's fine; if it sits for longer than 20 minutes but less than 2 hours, it's a bit flooded. Carbs are finicky animals.