Tuning help with new carb on strong 408

Hi All,

Have always been happy with my Holley 750 HP, except when starting cold. There is no choke and would take about 4 to 5 times of starting to keep running, then good. I purchased a new Quickfuel 850 with mechanical secondaries and electric choke. Throttle response is markedly improved. As with the previous Holley, I had to go with a 2.5 PV as vacuum is low...engine is pretty radical. I had the Holley off and on about 10 times getting it dialed in; squaring the transition slots, secondary opening screw and ultimately stepping up on drilled holes in the primary butterflies. I thought I had read everything about doing all this, but maybe I am all wet. The new Quickfuel is really rich at idle, as was the Holley when I started. The four corner idle screws have no authority at present. Do I have to go about drilling the primary butterflies again on the new carb to get the transition slots squared up again? I am sure that I am probably running on that circuit at present at idle. It worked out well on the Holley. What about the idle jets. Will installing larger ones help me at all? I am planning on a wide band A\F gage, but not installed yet.

Thanks........!!