Spark Plug Advice Needed

Thanks all for the coaching.
I had my distributer spun by Don at FBO and I just dug up the build sheet on it.
It says initial is at 16 degrees.
Vacuum timing can is 14 degrees at 14 inches of vacuum.
18 degrees at 3400.
I set the timing at 34 degrees at 3400 rpm with the vac advance plugged off and 16 degrees was the idle number it settled on.
And it's connected to manifold vacuum because it's so rich at idle it allows me to close the throttle at idle to close some of the transfer slot down. These 650 Edelbrocks are known to be rich at idle.
I hand lapped the valves and installed new valve stem seals on the heads last winter. Forgot to add that part.
Yes, these plugs have 100 miles on them puttering around. I'll change that on the next plug coloring trip.
Hope this clears up some of the confusion.