power valve size

I get what your saying. And I appreciate your input for sure. I am definitely a novice when it comes to messing with carburators. But when I bought this style of carburetor on the specs page it says these are designed to work specifically with roots style superchargers and have a boost ref pv that gets its signal from manifold pressure. So there a hose barb coming off the side that gets a hose that attaches to manifold vac. And that’s were I’m getting 6 vac at idle. Am I looking at this wrong?