Hot Rods Nailhead dual quad help

I have a nailhead dual quad intake and 2 standard 4 barrel can I use both carbs with idle screws I know the factory setup only has one carb with idle screws the big question is will it still work with both carbs having idle screws

 

what manifold? it will work either way assuming were talking idle mixture screws? or is it the idle speed screw your worried about?

 

Yep, I'm running the two fours on my 27 with just two regular Edelbrock carbs and both carbs have idle screws. Just adjust them both when you get it running.

Don

 

I ran a 401 Nailhead in my '55 Special with 2x4 500cfm Edelbrocks and it ran very good. Nailheads like carburetion.

 

Our 322 Nailhead loves 2 Holley 350 CFM carbs with vacume secondarys and both have idle screws that we adjust to get the best Idle, then turn them in slowly until the idle speed just drops. At that point turn the screws back out 1/8 to 1/4 turn.

 

On any intake both carbs will work with the idle circuit intact. On an intake with separate plenums it is essential as one carb works independently from the other. I will upload a pic of separate plenums for those who don't understand what I am talking about.

Now where it gets tricky is if you are running two carbs that have power valves progressive. Like Holleys for instance, the secondary carb will need a power valve with a different value than the primary to get it to tip in properly or it will need to be run power valve delete. If you are running the carbs straight up and not progressive this is not an issue. That said most people prefer the run the carbs progressive on the street.