67 dart emissions

I can tell you from experience that if you take it to a shop they will set it up to pass take it through for you and when they come back set everything back where it was and not tell you anything. I found that with my old F250 the timing had to be set at factory specs and the carb leaned. If you take it to a shop take it somewhere were they will tell you how to set it up or you will be paying $100 every year. Where in AZ are you, may be able to help.