360 Tune Up

Basics are this.
You can set the initial at X rpm.
If the engine will idle at 650 rpm at 16*, that's a pretty good place to establish as a baseline.
The problem, or potential problem is what happens as rpm increases.
For a street, road race or circle track using vacuum advance equiped distributor, its very easy to have too much advance below 3000 rpm.
A timing curve that looks something like the Mopar Performance shown in this post is the ballpark for a factory hi performance or hot rodded 340 or 360.
Your distributor is advancing way to quickly to be using a vacuum advance.
Begin with the guidelines and make small changes based on performance.
40* at 2200 rpm on up can do serious damage at wide open throttle under full load.
Full load is somehting like pulling a boat out of water, a 1/4 mile run - particularly the top gears of a 1/4 mile run.