New Engine, Hard starting, Likes Lots of Advance

Another factor is whether you are running "intake vacuum" (full vacuum at idle) vs "ported vacuum" (no vacuum at idle) to the distributor. FRANKLY until you get this sorted out I would leave the distributor vacuum connection PLUGGED. I think, but may be wrong, that most of us here run ported vacuum. There is, however a huge controversy about this. "The guy" at FBO ignition advocates running only intake vacuum.

What you use is going to "decide" what you need in the way of a distributor curve.

"Total" timing is nearly always discussed negating vacuum advance.

The "go to" starting performance cure is no more than 20 CRANK degrees of mechanical advance. This means 10 degrees is "in" the distributor

Start with intitial timing of 15 at least and sometimes as much as 20 OR MORE with a big cam. You can set this "normally" (No MSD) with a timing light ON THE STARTER

So let's say, mild cam, you start at 17? or so "initial" plus your 20 "distributor" is a "total" mechanical + initial of 37 degrees.

That then, is what you will see at midrange and higher RPM, and with your "foot in it" which "kills" all vacuum that is ALSO what you will see under full power even if vacuum is hooked up