670 holley avenger idle air adjustments?????

Forget this nonsense about "how many turns" except in extreme cases

How far in/out the screws end up depends on a LOT of things, including what sort of cam you are running.

Start with them anywhere from 1 1/2 -2. Get the engine fully warmed, and use either a tach, vac gauge, or "good ears."

Back them out until the engine speeds up, alternate sides

When the engine stops running faster, slowly, and alternate, turn them in a little at a time until the speed / vacuum JUST drops noticabley, then right back left "just a touch."

I always just "rough them in, recheck idle speed and timing, make sure it's warm, then reset them again.

IF they "want" to be way far out or way far in, this can indicate a carb problem or big mismatch to the cam and build.

If one doesn't do the same as the other, you have something plugged on one side.

If you have a fairly large thumper cam, often you have to crank in a LOT of idle speed screw, which draws the primary butterflies out of the "idle transition." Not good

Years ago, many people advocated drilling holes in the front butterflies, but this has proven unnecessary in most cases. Often, you can "crack" the seconary bores open a tiny bit (there's a screw!!) and this will allow the front idle speed screw to be dropped back.

Run as much initial timing as the thing will handle. My 360, which is pretty mild, runs 15* initial