The general idea on the 4 barrel……….
The rod 90° piece that goes into the slot on the center carb slides through/along the opening as long as the center carb is open far enough. The vacuum cans on the outboard carbs pull the outboard carbs open. They have a spring in each can (various tensions available) to help control the speed of the vacuum pulling them open.When getting on the gas. What triggers the two outter carborators to open up?