I understood the question as what cfm does a 6.1 intake flow- which can be answered by stating the throttle body is the restriction point, which flows about 800 cfm. If you open up the port, you increase the flow.
Correct me if I'm wrong, rat, but were you not looking for a comparison when sizing your carbs? If you were looking for flow bench numbers of a 6.1 intake on a single port- that I don't readily have available.
