small idle air bleeds instead of bigger idle tubes ?

[Frank400]

Just thinking out loud here.  What if, in a situation where more idle fuel would be needed because of going to a larger camshaft, instead of going with a larger idle tube and larger channel restriction, one would go with smaller air bleeds ?  Wouldn't the effect be the same ?  I've noticed quite large engines and/or high perf engines around 68-69 which had relatively small idle tubes/channel restrictions for the application, but the idle air bleed (upper) was kind of small.  Is that how they got by to get the idle fuel they needed ?  Any reason why this would or would not work on a later APT carb ?

[Cliff Ruggles]

Most upper idle airbleeds were in the main casting, just above the down channel restrictions.  They can be difficult to modify.

We try to come up with an average of .070" for both pairs for our basic calibrations.  If the upper idle bleeds are in the airhorn, they are "direct" bleeds and need to be a bit smaller, closer to .050" with .070" lower bleeds instead of .070".....Cliff