First let’s discuss how a carburetor works:
Carburetors work based upon pressure differential. As your engine draws air through the carburetor it creates a low pressure in the center of the carburetor. The difference of this pressure, and the higher pressure (from the atmosphere) pressing down on the fuel in the bowls is what causes the fuel to flow through the carburetor into the engine.
Now with that out of the way, if you have to jet up excessively from a carburetors baseline it usually indicates one of two things. It could be the carburetor being too large for the combination, or your fuel system not keeping up with the demands of your engine.
With that being said, going to a larger carburetor is not going to help you at this point. If your carburetor was too small it would actually run rich, not lean. The first thing to look at would be your fuel delivery system. A 110 GPH fuel pump would be on the small side for a supercharged engine.
As far as your original question, jetting by vacuum most likely isn't going to work on your current combination.