But there is more to power than flow. How about velocity? Two different ports nearly the same flow, but one is quite a bit smaller and better designed. Surprised at the exhaust flow on the 516 with those tiny 1.60" valves...
Further, chamber shape/design is very important as well, and this is where (in my opinion) the old B/RB just fails hard. If i was building an engine with zero deck i think the Magnum would shine even brighter in this regard... but thats just hypothesis.