As I mentioned above, I have not measured the vacuum levels yet. It's on the to-do list. I DO know that when I hook up the vac advance as-is, I get readings in the upper 50's to beyond 60 deg when holding rpm and trans in neutral. I also know that driving with it hooked up yields some noticeable roughness that goes away with the vac disconnected. So I'll simply be limiting the max vac advance amount to about 16-20 and seeing how that does.
