Carter Thermoquads ~ 'More General Information'

Bewy, if you sent your carb to a pro carb builder, believe me,
he'd be changing the air bleeds. that's why modern Holley, QF, etc. carbs,
all have tunable air bleeds, threaded in.
it's become the standard of the industry. tunable threaded emulsion bleeds in the metering blocks on a Holley design as well.
if you ran the early CS racing carbs, of course you didn't have to change air bleeds,
they were already downsized to the minimum size, richer metered, and not emission carbs.
the early CS carbs were in a different league,
then the later 72-up oem emission carbs.
1970's USA emissions carbs were white plug lean right from the factory, for the most part.
that's where the thermobog/quadrabog names came from.
they bogged right from the factory, cuz they were so lean, to pass emissions standards.
bogged and backfired out the carb actually. all the time.