Re: 454 LS6 Carburator help
That 830 is a race car carb, will get single digits gas mileage. they're pig rich in the idle transition because they were originally designed for racing use where there was no expectation of street use.
there's no adjustment for this, you have to take the carb completely apart and start drilling orifices.At minimum, to get this carb to a reasonable facsimile of a street car carb, you would have to change the Idle feed restriction, the idle air bleed, the accelerator pump squirter and restrict the fuel to the idle transition slot.
Truth is, you'd better buying a new Holley like the one linked to in Post #2. Beware of any local "Holley experts", they're not. Bigger is not better with carbs, especially with street cars. Chevy sold those engines in cars with a warranty, they had a 780CFM carb with vacuum secondary. The difference between 750 and 780 is piddling.
Tom Terrific or Terrible Tom, depending on the phase of the moon, passing cosmic rays or other factors not fully understood except by my wife.