I'm glad to hear you fixed the problem. The only thing I know about carbs idle is what I experienced on my truck. The idle quality is lower when you have a vac leak. My truck had other problems with it like a coolant leak and a bucking between 2.5k and 3.5 k rpm. Might have been related, but I wanted to swap the motor to get rid of the headache of a learning experience and just drive it.