Finally ended up at 18* base, NO vacuum, and 34* total.
Idles nice, Shifts into gear nice, and pulls like a striped a$$ monkey past 5500.
Tried like heck to get the vacuum to help but it messed everything up every time I connected it. Finally said Piss on it after seeing others with same issue.
Vac may be good with stock motor but mine does not like it.
Adding the vacuum advance may be an issue because you have so much advance in the base timing over stock; the vacuum advance addition is probably throwing in too much, too early. But if it runs well, then that is all good.
Sounds like I need to read up on 'striped a$$ monkeys'; sounds like a great engine mod! lol
For the OP, setting the timing is not all that dangerous but do be careful; we don't want to call you 'stumpy'....