The larger valves may increase volumetric efficiency (VE in Panic's post 9). He estimated 95 percent VE. Really difficult to get above 90 percent in a street normally aspirated stovebolt engine.

Note at 95 % the engine could use 441 CFM at 5500 RPM.

So at 90 % - 418

And 100 % - 464

Where is your absolute redline, and where is your practical (street) redline?

Jon

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
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