Poor throttle response

Carefully remove the front squirter (without losing the screw or washer :) ) and you'll see a number stamped on it. Add at least 3 to that number. Any less isn't a significant enough change. In theory you would keep going up in size till performance drops or you note black soot from the tail pipe on acceleration - then back off a couple sizes.

If, for some reason, you have to go larger than a 39 (.039") shooter, then you'll need to change the squirter screw to the hollow style.

If your car still has a lean stumble with the biggest cams and the biggest nozzles, you might then try a 50cc pump and the corresponding cam. The black cam is required on 50cc pumps to get the full shot of the 50cc pump.

FYI, the pump cam determines the volume of fuel the accelerator pump delivers (up to 30 or up to 50 cc's per 10 strokes) and the profile of the cam determines how this volume is spread out over the angle of travel.

The nozzles or "shooters" determine the rate of discharge. The smaller the orofice, the longer the shot will be spread out.