Spark Plug Advice Needed

When the engine was built the math did work out to a touch over 9:9 to 1.
Like I said before that Don spun the distributer and set all the advance and vac can for me.
I filled out a very long spec sheet that he sent me and he came up with the curve. And if you look at some of the first pictures I posted you can see the timing line just below the radius of the ground strap indicating the timing is really close to perfection for my engine.
I have some rods coming that will lean it out 8% at cruise and power mode. I'm going to try some hotter plugs too.