That's my point exactly about the head work- - - -bigger valves, opened-up ports, polishing, etc. It's the final step to making the dual-carb setup work, or any other enhanced carburetion arrangement. Then, all you've got is a high-speed engine. As long as there's one point of restriction, there's no advantage to doing the rest of the work. The possible exception would be if you install a pair of much smaller carbs than the single one it was originally equipped with, resulting in a slight, but useful increase in the total volume available. It's still only going to be useful at or near full throttle, but it's not likely to create as many headaches in the low speed and midrange areas. There won't be as much loss of venturi velocity that leans it out as the throttle is opened up from idle.
Jerry
