Power Valve Selection: The Definitive Answer

An enrichment circuit like Carters use is another way to skin the cat.
As far as enrichment at 14" - the question becomes why.
If the engine has even half decent fuel distribution, half decent mid rpm combustion, etc etc then it should make more power with leaner mixes until at least 50% load.
If the engine cruises at 16"Hg, 65 mph, 3000 rpm on a flat interstate, then it should not need enrichment with a hair more throttle (14"Hg) to go up a slight incline.
Does that make sense?

The engine described above should accelerate without enrichment at 14, 12 and maybe even 10". But seeing it has somewhat poor vacuum at cruise, its probably not a great part throttle combo, so that's why 10" is a maybe.

Just looking throiugh some of the 60's Chrysler FSM, an 8.5 PV was used on many of the Chrysler Holleys.
The well known 3310 Holleys used on some of the Chebby hi perfromance engines had 10.5 PV in the primary side and 8.5 in the secondary.
The 2bbl Motorcraft 2150 on my Wagoneer's AMC's 360 has a PV that staged to partially open at 9"Hg and fully open at 5"Hg.
So there's some real life examples of what some different engine combos need.