Zorro,
You only need one throttle link. It hooks to the cable at the back of one of the bellcrank "ears'. By turning the knob you minutely adjust the cable length back and forth thus syncing one carb to the other carb.
Once you have it set up, syncing is a "piece of cake" The picture a few frames up shows the proper location. If still in doubt ,give me a call @ 850-304-7371.
Dick