Classic over carburetion problem?

vacuum 750 is only a 375 2bbl until you allow the velocity of air through the carb to allow the secondaries to open up. That is controlled by a spring in the secondary actuator. Hard to overcarb a VS unless your jets are pig rich and your choking on exhaust fumes at idle and your AF is all out of whack. unhook the secondaries (just pop the actuator rod off the linkage) and run it. See if it acts any differrent. You can get heavier springs that will bring the secondaries on higher in the RPMs. I could light the rears on my 65 with my 340 with a smaller 284/.484 MP purple shaft but I had a 2800 stall and 3.91 gears but still, plenty of power. Heck I could light up 10" meats with a stock 68 340 and manifolds with a 3.55 7.25 SG rear before that. I had a AFB on that one, loved that carb...better response than even the VS holley. Maybe too much cam with that convertor?