Vacuum advance

If you take a compression test, you can get pretty close with the ignition cure the first time. It's just something you're gonna have to experiment with. Did you say you were running it 20 initial? I think you said you were going for 14 mechanical. What gear do you have? Maybe try it all in by 2500 and see. If you don't get spark knock, I'd call it good.
On the compression test I got 150 psi with the throttle closed. At the moment its set at 20 initial. I have 3.73 gears im at around 2900rpm highway speed (60mph)