How about power valve mixture, accelerator pump volume and velocity, part throttle transition, ported or full accessory vacuum, dashpot throttle closure rate, fast idle during choke operation, and about a dozen other tweaks that account for hundreds of different part numbers just for GM Quadrajet carbs alone? An engine might run with a one-size-fits-none carb, but performance and/or gas mileage will suck like a Dyson vacuum cleaner!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!