Fuel distribution issues arise when the fuel hits the plenum floor and is not directed in a clear path to a port. Just this week, I had the privilege of working two days on a dyno where we used single plane intakes, and dual plane intakes in comparison testing. The dual plane with ridges in the floor of the plenum did well in keeping the fuel in suspension, but the one with dimples did better, and had a better torque average as well as horsepower average. The single planes were the same manifold, but one was stock, and one I ported. The stock single plane had a plain floor, and at the top of the dyno pull, fuel was seen actually swirling and misting above the carburetor due to fuel bounce back on pulsation of the wave lengths. The ported single plane had dimples in the floor, equal flow in each runner within 4 cfm, and did not have any fuel mist or vapors swirling above the carburetor at the top of the rpm pulls. I am talking 7400 rpm, so it was not a toy. We made our pulls 3000 to 7400 rpm which is not normal, but stressed the engine to see how it would react. Headers, carb spacers, plenum work, valve lash, carb jetting all come into play when trying to maximize a combination, and I definitely am a proponent of equalizing manifold runner flow in cfm. After building engines for 57 years, I feel I can say this with confidence. Joe-JDC