Holley 4150 dripping fuel from primary discharge nozzle?

Square up the slot and locktite the screw. Adjust timing and mixture to get good idle. If you raise the timing you will get pinging. Have the dist advance modified to limit full timing to 34 btdc.-OR- you can also use an adjustable vacumn advance diaphram. Square the slot, adjust timing max to 34btdc without the vacumn advance hooked up, then hook up to manifold vacumn source and adjust the diaphram limit to the timing that makes the "happy" idle, that way you have 4 to 8 degrees btdc, cranking to start, "happy" idle timing when it starts( as high a setting that is needed, I have seen as high as 26 degrees btdc) and a max timing of 34 btdc. This way, you don't hurt the starter and no dist advance modifacation is needed.