One may ask :

But how do I set the timing before I start the motor?

It's actually easy.

Rotate the engine to compression stroke, with the timing pointer set to the correct timing.

With power on the distributor, take #1 wire and pop in an old plug, lay it where you can see it and its body is grounded. Rock the distributor back and forth, looking for spark. (No spark? Something isn't right. Look to see if the rotor is actually pointing at #1). Keep rocking back and forth ( quickly) and guesstimate where it is actually sparking. Lock it down just tight enough that it takes a deliberate effort to turn it.

This method will get you +/- 2*.