Carter Thermoquads ~ 'More General Information'

I agree, the idle jets are not huge
I said the primary and secondary main jets are huge.
137 and 143 jets on secondary from the factory is huge for an OEM,
it's bigger than what a factory Holley 1150 Dominator came with.
TQ's had 92-100 primary main jets as well. that's very big.
the last 1150 I bought had 92's all the way around, and even THOSE were rich,
because it was a carb with no power valves, so the jets were 6-8 higher than what they should be to start. a Dominator with power valves can run 82-86 jets.
137 or 143 jets are what racers run in alcohol fueled cars, typically 50% higher jetting.
talk to the carb builders who build carbs for $600-$1000 a pop for past 50 years,
when the idle/high speed bleeds in the top get over 70/30 respectively,
and a lot of emulsion jet is used in the metering blocks, i.e. 3-5 per side,
instead of the factory 2 per side, the carb goes nuts.
it becomes like a Binks #7 spray paint gun. turn the air pressure up and down on a spray gun, see which setting pushes more paint out of the tip. if you add a lot of air, there's not enough paint, it goes thin and lean, and you have to open up the fluid setting to mix more paint in to cover. turn the air pressure down, all of a sudden there's too much paint and it's not atomizing, and you have to turn the paint knob in to lean it out.
it's also why a Qjet biggest jet was 78 even if it was on a 500 CID Cadillac, but a Carter TQ had a 104 jet available for primaries. It makes me wonder why?
measuring those air bleeds in the TQ lid, no other carbs I know of, have 2 idle circuit air bleeds in the lid per primary bore. and no other carbs have high speed air bleeds that big either. normal size for a Holley is around 30. the TQ's have 42-52+
the secondary side of the TQ appears to have a normal sized high speed air bleed, 29-38 range.
with all that air bleed on the primary side, the TQ was obviously an emission carb from the get go 1972-onward. This is why the later TQ's are $25 each, but the early 1969-71 CS carbs are $500+ each, if you can even find one for sale.
another tricky factor with a TQ is secondary air valve opening. if the air door is adjusted to open more or less, or open quickly or slower, it affects the mixture dramatically. the air door is like a giant adjustable air bleed. it must be adjusted precisely and specifically for each engine application. the biggest factor is engine size. what works great on a 455, is too quick and bog city on a 350. a bog is a lean condition, too much air too soon.