Tim is correct on the airflow. Having the choke butterfly functioning actually IMPROVES airflow at lower RPM (probably below 3500 or so).
With 2 carbs, both should be IDENTICAL for best results (unless you are looking for the absolute maximum WOT horsepower and have access to a dynamometer and some sophisticated individual cylinder temperature measuring devices).
Not saying it won't work the other way, because it will; just not as well.
Jon.
