440 Help Needed

I have a 1972 Olds 442 with a 455 and the compression on the cylinders is in the 185-200 PSI range. Runs fine on 93 octane, but you need to carefully tailor the timing curve. I usually like really fast curves with about 20 degrees in the distributor 16 initial and all the timing in by 2200 RPM or so. This engine will not tolerate that on 93 octane fuel. I had to lower the full advance to about 3500 and it works fine.
Either way a high compression ratio will not affect idle quality at all. Have you checked your fuel pressure? What fuel pump are you using? If you have a carb that is running that rich at idle usually you have fuel bypassing your needle and seats and just dribbling out of your primary and/or secondary boosters. A 440 with a 236 @ .050 cam is nothing out of the ordinary and you should not have to open up your idle air passages. With the car idling and the air cleaner off, look at the boosters on the Holley carb and see if you see fuel coming out of the boosters. If you do you have found your problem. What is strange is that this happened with 2 different carbs, which means that there is an inherent problem with the car and that it is most probably not the carbs fault. Too much fuel pressure (anything over 7 PSI on a Holley) will be too much pressure for the needle and seats and they will leak. Only other thing I can think of is just a lot of dirt on the fuel tank that is getting to the needle and seats and just not letting them close.