Anybody know about this intake? 318 single plane 2 barrel

I think his concern isn't so much the top end, but the streetablility.
He read the same magazine experts that we all have, and they all say that a single plane is really best for high rpm.
So imagine how torquier and better milage the 318s would have got back then if they only had used a dual plane!

Seriously I think the magazine experts generalizations are fine for what they are, but plenty of examples where other design factors result in exceptions. Under low throttle a 318 has strong vacuum and fuel distribution is going to be good. As throttle opens runner and velocity probably keeps the distribution pretty even. Other plusses were lower weight, and better fit under the hoods of the compacts.