Carter Thermoquads ~ 'More General Information'

notice in his 3rd tune/test, all he did was reduce air bleed by .017"
rods/jets stayed the same. presto- magic.
that's how fine an adjustment we're talking about. pin drills.

think of it this way-

changing jets/rods, reading plugs, is hot rodding 101.

getting into the various air bleeds, is carb guru stuff. like what Barry Grant, Nickerson, Jet Performance did on Holleys, Qjets, etc. that takes it to the next level.

a lot can be done by swapping a 400/440 carb, onto a 318/340/360 engine, because the bigger engine was usually metered richer at the factory due to its sheer size. but not the other way around. put a 318 carb on a 440, it'll may end up blowing flames out of the carb, too lean.

that's where 440 Cuda's old posts were so handy, you could choose a rich metered carb from his "good" list. that was a great starting point. he understood the system that was in place in the 1970's.