I brought it up to TDC by putting my finger over the spark plug hole of the number 1 cylinder and had someone bump the starter until the air pushed my finger out. I looked inside the cylinder and the piston was at what seemed liked it's highest point closest to the spark plug hole.

The 9-12 degrees was estimated since I don’t have a timing mark to go by. Since 12 degrees is about a half an inch in front of TDC on the timing cover, than I used that same distance in front the current tdc location to determine the amount of advance.

So given all the estimation, I could have been off enough to be beyond 12 degrees. To be safe, I'm going to back the advance off to just before TDC and see what happens both when it’s cold and after running it a while.

If I still see an issue, I'm going to switch the starter out with a known good one and go from there.

What’s the recommended amount of advance if you have an aggressive cam? Or is it different per cam?

Eventually, I'll replace the balancer too to eliminate the confusion.