Sizing carburetor

This is a decent article that talks about the baseline carb sizing. There's a lot of grey area, but it provides a formula for guidance. https://www.motortrend.com/how-to/much-carburetor-need-application/ Perhaps the most 'arguable' variable is Volumetric Efficiency (VE). If anyone knows of a solid reference in determining (somewhat accurately) the VE, it would be a great post.

Mike