[RET_COP]

Make sure there are no vacuum leaks. Check your initial timing. Once that is done set your idle and adjust the mixture screws. The mixture screws should have an effect on the quality of the idle. If turned all the way in the car should stall. If not you'll need to pull the carb off and look at the throttle plates. The transition slots should be seen under the plates. about .020 is good but there is leeway. I try to get them balanced. Sometimes I'll set the primary at .020 and the secondary at .020 and use the secondary for minor adjustments on the idle. The primary plate may be open too far and out of the transition slot range causing the car to stumble due to ---well---no transition from idle to main circuit. To correct this you will have to open the secondaries up a little and you will be able to close the primaries--hence the balance I stated earlier.
Good Luck
Lou