and one head back together... About 3+ hrs to take one apart (and mark), smooth out the burrs, clean thoroughly, and reassemble. The exhaust valve marked "D" is about .008-.010 higher (at valve stem) than the rest (the rest are equal) with a flat edge.
Did you figure out the valve length issue? If it's the seat causing the problem could you machine some off the stem to correct it or is .010 nothing to be concerned about?