Flutter below 2k rpm

Having played with a 800 AVS on my 408 motor I have the carb setup in a weird way that I haven’t been able to wrap my head around. This is race only though so keep that in mind. I have the primaries 3 stages rich and the secondaries 3 stages leaner. So you figure, put them both back to stock and the WOT AFR should be the same, but nope. It stumbles like you wouldn’t believe. I have seen the same thing with a dual quad hemi running eddy afb’s Only liked real rich primaries and lean secondaries. It might just be a bandaid for transition. I don’t know.