There is a slot inside the throttle bores. The secondary throttle plates should be set open .020 (pretty sure that is the correct number!). The adjustment is on the bottom so the carb has to come off.

The likely issue is you are having to open the throttle blades too far into the transfer slots to get 650-800 RPM in gear and 1000 RPM +/- in neutral. You will likely have to drill 1-2 small holes (or drill and tap for a small jet or IAB) in the top of the carb to allow more air vs. opening the throttle blades more. The easy way to check the RPM spread is by idleing in gear and while using a digital tach to adjust the throttle blades (carb linkage) to get the lowest RPM without stalling. Now shift to neutral and see where the idle goes. It it goes much above 1000 RPM (likely) you will need to drill a hole in the top of the carb in introduce air so you can reduce the opening of the throttle blades. This is a common Dominator trick and is now standard on Holley's newest generation of 2 & 3 circuit billet Dominators.

if you need to turn the idle mixture screws out more than 2 turns you probibally need larger idle air bleeds providing the timing is good,check it with an advance lite,you might need to lock out the distributor.

Burn my eye's!! i never go futher than 3/4 turn..anything over 1 turn and its all fuel..they like to load the engine with fuel over 1 turn unless you have a really big blower on top :P

That's actually backwards. Larger air bleeds would make it leaner, requiring you to turn the mixture screws out further.

Lots of timing and a little bit richer, as others have said, are the best bet.

when i set my quickfuel carbs up they told me the larger air bleed wll cause the carb to pull more fuel;they were right as it worked,im no carb expert,just stating what the experts at quickfuel told me.

haxby,i just looked it up,you are correct,i had it backwards.

timing should be at 36? and andy that's what I did with the blower motors , but im a little rusty and these were more bi polar, if you know what I mean.

I was having the same problems, Make sure your throttle plates are even and within the small transfer slots or you will lose idle mixture control. If you need more are than that, start with 1/8 holes on the inboard side of your secondaries. The best thing I can recommend is to lock your distributor, I'm running 34 degrees, but I'm also at 10.1:1 compression. I had power valves that were fully open at idle and didn't notice a difference. I've been told that you won't pull fuel through the PV circuit until you get enough air velocity.

if does not like to idle, might have to lock dist and set timing around 30 and see how that works...cleans the idle up...