So the best dual plane was equal to a basic single plane?
Sorry, you picked up 3 thousandths. With a dual plane. Not convinced.
You can have 5 different dual planes, and each one could be "the best" one on 5 different engine combo's....
Sometimes the engines actual "performance" is in the heads/cam & trapped charge, think "positive harmonic" .
Sometimes the intake does nothing but hold the carb up.....
Also, why would you run a 4 hole tapered carb spacer on a single plane? Did you purposefully choke it to prove a point?
Your kidding right ????