Performance timing

Another way that may be a better fit for you is follow 512stroker's procedure on page 1, post 12.
Set the timing at 15 and take for a drive, see how it feels and if it pings at WOT in 3 or up a hill.
Then try it at 17*
You'll still want to adjust the idle fuel mix if needed.
When testing for ping going up steep hills and at WOT, no vacuum advance.
If it pings, reduce it back to 15* at whatever rpm it was for the first test.
When its OK without vac advance, then connect ithe vacuum and test again. If it pings at part throttle or light loads, vac advance will need to be adjusted. If no pinging, you can call it done.