Help! Dies At Idle In The Cold

[2B32]

I have a 71 w/350 and Edelbrock 1406 carb. It idled fine in the summer, but now that it's cold it dies at idle. It runs fine as long as I keep my foot on the gas, but sputters and dies as soon as I let off. I checked the choke and it's fully closed. Also, the vacuum line from the distributor is plugged into the timed vacuum port for emission controlled vehicles. Should it be plugged into the vacuum port for non-emission controlled vehicles?

How do I fix this? This is my first experience with a carb, so pardon my ignorance.