What is the gain using these? I can get a deal on a set with all the adapters and hardware pretty cheap for Pro 1200.

What gain should I see? Been told that no adjustments need to be done on the carbs as low end ajustment mixture screw is't really effected by additional air, the mid or highs on the stock carbs are jetted high enough that adjustment isn't needed or possible (no mixture screws)

Is what I have been told accurate?

Also switching to 15/21 impros blueprinted concord impeller with AAT.

This slight mods going to provide what type of performace gains?