holly carb issues???

From what you have posted the power valve and jetting are not a issue. I believe you have to be rich from pressure or float adjustment. If you are only running that stock mechanical pump, which i have done with Holley's many times, then i'd have to look at the float's. When you get it back together and make sure the fuel in the bowls is not above the sight holes i think you may have cured the problem. Might want to throw a set of new plugs in afterwards to get a fresh reading.