I'm fairly certain that Marcy Motorsport has flow-benched a head. The number that comes to mind is somewhere around 300 CFM, but you'll want to double check that with someone who remembers the exact post.
I'm not used to thinking in CFM, but I do know that small V8s will commonly use carburetors that flow around 600 CFM. Half of that seems very good for an engine less than half that size.
You may want to start a new thread, to see if you can get Marcy's input on the flow.
