I do all my adjusting with the linkage unhooked. I start with with the throttle screws backed out so each throttle blade is 100% closed. Then, using either a dial indicator or feeler gauge, I open each to the same spot. I set them where it should start and run, at this point I am looking for it run, not so much a set rpm. The idle screws are set identical as well. Once started, I can then adjust for idle speed after it warms up. You need to be sure to turn each adjustment of each carb the same amount, its a lot of jumping back and forth. I have used the air flow gauge which helps (http://www.speedwaymotors.com/Edelbrock-Uni-Syn-Carb-Synchronizing-Tool,267.html ). I also use a air to fuel ratio gauge stuck in the tail pipe, which really helps when setting the mixture screws, with two carbs, a little goes a long way.
Once they are set and the idle is correct, I then set up the linkage being sure not to change the throttle positions.
Joe
