The curve on one end of the head it starts eating into from standard height. Looks really bad when you get 10 thou into it :p Looking at the inlet valve height it hasn't had much taken off.
And I meant the valve seals, not the valve stem seals. I.E are your valves actually sealing against the cylinder head or have they moved/bent/been compromised in some way. Much more hassle to sort when the heads back on again.