Just an update on my head situation. Instead of cutting down a perfectly good head, I decided to make a one piece head out of 6061 aluminum. I did raise the compression just a tad. I am still using the 2 shims also. I just lowered the glowplug .015" farther down inside the cylinder.
How does one know if the compression is too high? Will it run awkward? Not hold a tune? Or eat glowplugs?