Older cars have a limit of material removed during resurfacing of 0.020(twaintee thousandths) of an inch after which you discard the cylinder head. With today's bimetallic or aluminum engines it is highly discouraged that you have the cylinder head resurfaced. They are made thin enough to reduce the weight. Check the head for warpage first. Of course the machine shop will not refuse your money.



By the way, you can replace the valve seals without having to remove the cylinder head.