1 & 2 are a fixed set, as are 3 & 4. the adjustment to balance the throttle blades is the screw between 2 & 3, this aligns both sets, or all 4 to each other. if they are close, or to fine sync. them, use the air screws on each tb. changing one will affect the others slightly. u can do it with a single guage, but it can be a pita dealing with the screws angle and location and reconnecting the guage as many times as needed. as for me, id use what i have before i bought another set. a little patience and youll be fine.
Last edited by gazx10; 04-21-2011 at 10:50 PM.