Link and sync on a V76 dont require any special tools just time. You start by turning idle screw out disconnect center links and throttle cam. Set one set of carbs to all closed and working together, then set the other side the same way, then setting the center links so both sets work together and at the same time, getting the slop out of the center link is touchy. This is a good time to adjust your tps also. It is best to get a manual or at least a generic manual to help as there are some measurements also. How often? Personally I only do it if I suspect a need, I would check the throttle plate movement of each carb before I disconnect anything. You could spend a couple hours making fine adjustments. I use a dial indicator myself for dead accuracy, every mechanic may have a special procedure they come up with.
