I have bought custom built carbs. from a big name shop, one worked real well and another one didn't I have since bought and dyno tested a high dollar custom built 1050 Dominator unit against a stock Holley 1050 Doninator 9375 non HP and the stock Holley made more power and had a better BSFC I have also heard from several different really good machine shops with good dyno that they have seen the same thing on many different custom built Holley type carbs. The same size stock Holley worked better than the custum built units did I'm still in the dark about sone parts and theory on carb circuits but owning a wide ban helps a bunch on tuning the diffeent circuits in the carbs.