When you say you are limited by 10” of vacuum do you mean your max vacuum is 10” ?
The lowest can I have seen is an 8.5. Which means it gives you 17” of crank advance. So I doubt you need to file your for more advance
10 inches at 850rpm idle, it does go up with no load rpm
The advance I have is adjustable, 46* verified with a dial back timing light, is the most I can get out of the advance adjustment.
