Vacuum advance tuning to maximize cruise MPG?

md
Are you saying that your current can has 22* in it? Is that before modding? Me want,one! There should be a number on the arm; any idea what it is. Whats it out of? Im so jealous.

marked 11R on the arm
77 Dodge B200 360 2brl 10-12*@12.5" dizzy #3874115