The Holleys that are more 'tunable' than a Carter/Edel AFB/AVS cost a LOT more! [ Post #40.]
The Holleys that are a similar price to an Edel carb have fixed PVCR. On a Holley, this orifice adds the extra fuel for WOT. If it is too big, I guess it is bad luck....
If it is too small, it has to be drilled out. Also, many Hs only have a sec metering plate, not a sec met block. The plate does not have removable jets, so.....
With carbs like the Edel that use met rods & jets, you can find a combination that satisfies cruise as well as WOT requirements. Secs have replaceable jets for ease of tuning.