Autozone distrubutor vacuum advance locked?

You have to disconnect the vacuum. Drive it, and keep retarding until the ping stops. That is your total. Now, will it start hot? will it idle ok? If not:

Figure the total, now move the dist to where it starts and idles good.
Subtract both numbers, idle from total.

That is the total in the dist needed, get that locked in, welding, adjustable dissy, etc.

When that works, hook up the vacuum, see if it likes it, then adjust the can. The vac advances it more, under cruise, just for gas milage, don't be surprised to see 50 advance at that.