The spec reads like this:

Max warpage .5mm (.020)
Max machine .5mm (.020)
Max warpage and still be machinable 1.0mm (.039)

What this means is that if your head is warped half a millimeter or less just bolt it back on and run it. If it is warped up to 1.0 millimeter then you can machine it half a millimeter to the point that it is only warped half a millimeter and then run it. Max head height as I recall is 146.1 and minimum height is 145.6, something real close to that if that isn't the exact number. In the past the only problem I have had with getting red engine heads to seal up is when some newbie at the machine shop puts too coarse of a cut on the head and then they leak everytime.

Mark