For the most even fuel distribution, a intake would have to be designed like headers. Equal length runners. Dual planes get as close as engineering will allow. That's why individual carbs/cylinder (like Weber) or port fuel injection works so well. Every cylinder gets the same mixture. Think about how in-efficient a 6 cylinder is with a single carb right in the middle of all the cylinders. The further away from the carb, the leaner they get.
