[elmariachi]

I did a bunch of reading so don't quote my way as the best or only way. On my car if I have the idle screw turned in too much the carb will stumble as it transitions from idle to acceleration. If I set both carb idle screws so that the slots are .020 square, the car will start and run (once warmed up) at about 650 rpms with my 294 Comp Cam. To get it to idle where I want it at 850 rpms I adjust the front carb only. I then hook up the linkage, then adjust the back carb idle screw in until it starts to raise the rpms, then I back it up a tad until its at 850 rpms. Once you check your vacuum and idle mixture you may have to do this all again one time. Lastly I set the float bowl levels so that fuel is just below the holes with the bowl sight plugs out.

One other thing to check with them on the bench...make sure you have discharge needles in the well beneath the discharge nozzle/squirter. The exploded diagram shows a check ball, a weight and a needle in that hole. You either run a needle only, or a ball and weight but not all three. Lots of times when carbs are rebuilt these items get overlooked. The missing needle will cause the carbs to continue sending raw fuel up through the squirter nozzles when you let off the gas, impeding a smooth and quick deceleration.