Holley carbs ...

I've got one on my rebuilt with mods GM 305 . I'm having problems getting it dialed in , not surprising since this is my very first ever Holley . The carb in question is an 1850 600 cfm with center pivot bowls from a 3310 . Stock jetting and metering plate . The motor is a 305 bored .060 over with flat top pistons for about 9.7:1 C/R , Elgin E-922-P cam* , small tube headers and an Edelbrock Performer manifold .

*cam specs are .444 /288°(214 @.050) intake .463/298° (224 @.050) exhaust , lobe centers 107/117 and 112° lobe separation . One problem is getting it to idle properly . I had the idle speed screw in so far the transition ports were halfway uncovered and the idle mix screws had no effect . On the advice of a Motor Trend article I drilled a .093" hole in each of the primary throttle plates , which allowed my to close the throttle enough that the mixture screws now have an effect - but maybe not enough , as I'm only about 1/2 turn open on the mix screws . I'll be pulling it off to see how much of the transition port is uncovered , might need to enlarge those holes a bit or open the secondaries a touch , another suggestion from that MT article . The other problem is that it seems extremely easy to flood the motor . I hit the pedal once and pull the choke partway out (it's like 90° out) , turn it over and it catches then dies . Pump it once more and open the choke a little bit might fire , but it seems to take a lot of cranking to get it lit . The floats are set dry centered in the upside down bowl , I can't keep it running long enough to adjust the level . It was loading up at idle - I think due to unmetered fuel from the transition ports - and spark plugs were carboned up , tailpipe is sooty too . I'll be picking up a new set of plugs next trip to town . Any suggestions at all will be considered , just don't tell me to inject it cuz the wife is already thinking I'm spending too much money on my toy ... doesn't help that I found a rock embedded in the drive belt of my Harley this morning , that's another (transmission/primary drive repairs/replacement) project that's turned into a money pit .