Vacuum advance tuning to maximize cruise MPG?

I edited post 22, to maybe help explain my thinking. My thinking may be getting fuzzy in my middle tears. And Im not too proud to change it. So the new part starts at "consider how it works".

46* @idle, 60* @ 2200. That cant be good. I consider that messed up.
The object of this exercise is not to force the engine to accept huge amounts of timing.
The object is to give it only as much as it asks for.
If you start the fire too early,Then 2 things can happen; 1) The peak pressure will occur too early, at a place where the rod cannot deliver it efficiently to the crank, and 2) the pressure may be too high before TDC and it may actually try to force the piston back down, the way it came. This is sometimes called negative work. This was evident when you had to increase the idle speed when you over-advanced it to 46*idle timing There may not be enough pressure at small throttle openings to cause the dreaded rattle, but none-the-less, it may be too much, and will eventually lead to bearing damage.Thats why I called it messed up.
-Once you get the dial-back installed, you will be able to prove this quite easily. I suggest you set the base timing with the device set to the middle of its range. Then you will be able to retard it as well, from the front seat as you are driving. If the MPH goes up when you retard it, you will know its too far advanced. If it changes very little, it may be advanced way to far.
Yeah so, Ima gonna be gone for a few days, So Id like to say Best of luck to you and may all your efforts pay off.