Our big blocks tend to like the advance all-in as quick as possible as long as it doesn't ping under load. Small blocks tend to be less picky. But you do not want the advance to begin until the RPM is above the idle. If it starts advancing while idling, you will be chasing the idle speed all the time, since the advance will be changing with engine speed especially when dropped in gear if an auto.

For a big block, I like to try for advance to start about 1,000RPM and be all-in by 1,500RPM. Then check to be sure that there is no spark knock under 2,500RPM. And the more overlap in the cam, the more advance they like in the idle. Most of my big blocks (and my current Hemi) have 25* to 28* advance at idle. Basically, all I can get before it starts kicking back against the starter.