Happened today, coming out of a parking lot. Hit the brakes pretty hard doing about 20, and it stall before I had slowed to 10. The car is running very rich, and the timing is a bit retarded (to deal with a ping), if that might be an issue.
1. Do you have the Air Horns installed on the carb?
2. Have you adjusted the float height on the rear bowl?
Couple things could be happening:
Your float level might be correct, but you removed the air horn so when you stopped short the gas runs out of the vent and flooded the car
Your float level might be too high and with or without removed airhorns you flooded on a short stop.
The float might be sticky in the rear bowl allowing the bowl to get too much gas in it and it flooded the car and usually drips down the intake under normal running and causes you to run rich
You may have sunk the floats in both bowls on the short stop causing it to stall.
You might.....well I think you see the pattern...its all carb related
Do you know how to tune your carb? I have the same style and it is very easy to do. I did a search on the web and came up with this http://www.carcraft.com/techarticles/1071/
I would retun the idle and get it to the proper mixture. You may have been helping the situation with the rich mixture IF the choke wasn't operating correctly. Check to see if it is closing. Then check the idle rpm. It needs to be idleing around 1100 rpm when cold, and the fast idle cam will take it from there when it begins to warm up. I suspect, that it was cold, not much choke, too rich, timing too slow, and idle speed to slow.