What is meant by 'correct' here? If stock, per the factory, that may not be good enough. Stock timing in the smog era engines was retarded for emission purposes and that, plus higher temp t-stat's (also for emissions purposes) resulted in dieseling becoming more and more of a problem. Anti-dieseling solenoids were added to many carbs as a band-aid to fix this.
The other thought is that the secondary stop screw is not set right. That may force you to set the primary too far open and allow the dieseling problem.
