Vacuum Advance Question

OK...
I got a Mancini Distributor (non adjustable vacuum advance). I wanted to be able to FINE tune my timing so I replaced the non adjustable with an adjustable. When I started my Dart, I got a big 'pop', not like a back fire.
I disconnected the vacuum line to the distrib and restarted the car and it ran fine, just needs timing adjusted.
My question is, what should I do to set this up initially? I guess an example of what I'm talking about is the mixture screws on a carb; when you first set it up and you bottom them out then back them out so many turns.?
This is basically a stock distributor that I want to put a stock 'adjustable' vacuum advance on.

Thanks,
Eric