Hmmm...kinda sorta. I don't know just how much of this stuff you know, okay?
These days, initial timing works around 12-14 degrees. You can't go by the setting in the manual, since back then...different gas. Have to tune for the gas, and the engine.
If you pull the distributor cap, you'll see the rotor. By hand, twist it, and it will turn a given number of degrees. Should move back, once you let go. That movement is the mechanical advance, set in the distributor, under the points plate.
Just saying, for the initial timing, 12 degrees BTDC (0), and getting full advance where it should be, that mechanical advance should be adjusted for it.
Stock distributor? Some are adjustable, some are not...but, with ways to fix it. Of course, the distributor needs to be working right, in the first place!
Yes, use a timing light to set initial timing, at the timing marks. But, you also need to know how much ADVANCE your getting, for it all to be right.
If your advance is not right, and going more than it should...could be why it was running like you said.
There's tons of info out there, on this stuff.