slv: "linked and synched"? forgive my ignorance- what is that/how do i do that?
best way is with a manometer. You can make one at home tons of articles out there on how to do it. Basically, it measures the vacuum your carbs pull, and you have to adjust all the carbs to pull the same vacuum. A fairly easy way to do it is just loosen all your links to the carbs, and slowly tighten, to that all 3 butterflies open at the exact same time, and exact same angles, and they are all opening fully(about 4 degrees off of completely horizontal).