Not understanding; not a challenge to your experience but trying to understand why. Dual planes have more twists and thus suffer for breathing efficiency. Single planes can have more issue with equal mixture distribution at lower RPM's but use a moderate rise manifold, a torque cam, and not the largest runner sizes and that will tend to even out. And a torque cam will not cause the reversions that are common in wild cams that send a lot of flow distrubing pulses back into the intake. So, IMO, there is an association of single planes with high RPM, wild cam apps that holds true only in certain conditions. So just curious.....