Stop in for a cup of coffee

Hey guys. Out in town driving the 69 dart. Cant keep idle constant. Power valve?
Possibly but I would check the timing first to see if it's bouncing around. I had a worn distributor in mine when I first got it and spent a month chasing what I thought was a carb issue only to fix it by replacing the dizzy. I only figured it out after spending a lot of time with the timing light reving and idling to see it drifting all over the place.