Have a vacuum advance question when timming.

Stock timing is 6° BTDC at idle. There is a lot more to timing than "total". I'd suggest having the distributor professionally adjusted, it'll make a big difference.

Yes, the engine will run fine with the timing at 0° (TDC) but mileage and performance will suffer.

Those specifications are intended to be used with the distributor mounted in a distributor machine.

"Total advance" adjustment is a kluge used by people who have no access to such a machine. Total advance is only a small part of the adjustment, the curve, or rate, at which both the vacuum and centrifugal advance arrive there is far more important, making the difference between the engine being a dog or a tiger. If no shop in your area has such a machine in this day of computers, there are places where you can send them.

Hi,

If you are serious about having your dizzy, both, checked for optimal operation and determine it's performance potential, then, send it to a specialist. I had mine rebuilt a couple of years ago. If you don't already have someone in mind, PM me. I didn't think it expensive for what I got in return and learned about it. This is even more advisable when building a performance engine.
Happy Trails!