[ERA Chas]

Dan-
Use a vacuum gauge on each carb at idle. Motor should be operating temp-about 160 water or higher. First baseline the mixture screws at 1 turn out. Then do one at a time in 1/4 turn increments and see where highest vacuum wants to be. Go 1/4 turn past best reading to confirm and then go back.
Assuming idle has picked up and steadied, reset idle speed screw and see if you can get 800 smooth(er) idle.
For advance, I'd use more initial (18 or more) and about 38-40 total. That too will raise idle so readjust speed when it's stable.
Edit-Make sure float levels are good first-I'd start with fuel at the very bottom of the hole.