When you unplug the hose off the advance does it still "surge" at cruise speeds. I really don't get the "don't want to use a timing light thing" It's hard to give guidance when we don't know where your timing is. It's like the guy at the track complaining about his car running slower than expected and you ask him where the timing is set and he says "I've had it everywhere" Not a very intelligent response because timing is more important than ever with the crap fuels we have today.
Set your total at 34* without vacuum and see how it runs

Gus