When does the total advance come in? What cam? My 512 with the C8 heads liked 34 total at 2900 rpm's. I don't think your tune is quite right.
It is open.Is the 2 inch spacer open or a 4 hole? That carb is going to be big and if the spacer is open it may be losing signal as well.
Not as much as I would like LOL! I ve got it chipped at 7000.......depending on the track, but usually around 6500-6800.What kind of rpm does this motor see on the top?