Carb Tuning

I noticed that the idle mixture screws on my Edelbrock Performer 600 were turned out about 4 turns. I did not ever remember doing that. So I screwed them all of the way back in, then a full turn and a half back out. How far should these be adjusted out? I readjusted my idle speed to compensate for less fuel at idle and to bring the idle speed back to where I had it. It seems now that the COmp XE268 cams lopeyness in my 318 is more present now, which is ok to me, as it sounds good. It is not misfiring. Is this because it is not as rich of a mixture at idle as there was when the screws were turned out farther?

Cruising, it still runs great, since these have nothing to do with fuel mixture at speed.

Also, is there some kind of phenolic spacer I can use under the carb? It is heat soaking and requires a few more cranks to start when warm. If I take the air cleaner of and listen to the carb when its warm to hot, I can actually faintly hear the perculation of fuel in the bowl.