Plug read, opinions needed

TT5.9mag said
That is interesting. It’s amazing the amount of information that can be had from examining the exhaust gasses present post combustion. Although I’m guessing my smog guy would laugh if I brought a twin turbo big block in for a smog check. This engine has a dedicated blow through CSU carb that Kevin built for it. It surprised me when he sized it at 750cfm for the power goal I gave him, and when I asked he said with the smaller 750 and the annular boosters you’ll have great response, lots of signal, and better atomization than if we used a larger throttle bore main body. Maybe he’s on to something.

Carb sizing is relative to the engine and its ability to vaporize the fuel. Bruce said he had seen engines that need 3 inches of vacuum at WOT to make best power and others only as little as 1 inch. Vacuum plays a part in gasifying the fuel from its liquid state as liquids don't burn gasses do. He said that there were mainly 2 places to do it, one was the compression stroke by compressing the mixture (valve timing) and the other was using vacuum to do it the inlet tract. A smaller carb increases the vacuum which in turn increases vaporization of the mixture before it gets to the cylinder. Which one do you think will improve mixture distribution between cylinders?

Shrinker Intake valve closing and carb sizing:

If we look at the influence of intake valve closing point we find that at some point when the piston is coming up the compression stroke, the pressure in the cylinder will be the same as the intake runner. If we shut the valve after that point in time we have shut it too late. Once the pressure in the cylinder exceeds the intake runner the air will go back out of the cylinder. If that happens we can do something about it without tearing the engine apart, we can install a SMALLER carby. What that does is it restricts the fill of the cylinder so that the incorrect closing point of the valve is not incorrect any more. Essentially a smaller carby makes the cam appear smaller. THATS one of the factors why sometimes engines make more power with smaller carbys.
Our own drag car has had various cams ranging from 269 to 289 intake duration in it, the longer the intake duration the smaller the carbys had to be to get max power out of it. And with all the different cams its always made exactly the same power because we never changed the head flows. BUT i had to make the carbys smaller to get the power back with each successively larger cam. Every time we went larger in the cam it lost power on the old carby size.

Now read this article and ask yourself why the smaller carb ran the quickest:

How to Pick the Best Carburetor for a Street/Strip Car

By the way the 650 had 5.5 inches at WOT......