"Double- - - -double- - - -toil and trouble!" Running multi carbs with progressive linkage is like diving headfirst into a witches' brew! Find a carb that's approximately a fraction of the total CFM you want to run, and then build several of them as close to identical with each other as humanly possible. The laws of physics are not "suggestions". If a single carb is designed and calibrated to run an engine of 100 cubic inches, for instance, and you want to use it on a 400 cube engine, you'll need FOUR of them running in synch to flow the right velocity through the venturis. (Honda Gold Wing, for instance) Trying to tip in extra carbs with different throttle plate openings is a disaster looking for a chance to happen. The Pontiac Tri-Power and Olds J-2 systems ran the two outboard carbs in a "wide open or off" situation. They didn't even have idle circuits. Ditto for the secondary carbs on the Corvair Spyder 4-carb setup.
The two most common rookie blunders hotrodders commit is "too much cam" and "too much carburetion". Mother nature can be a real female dog when you start tinkering with physics.
