I've noticed a few things here lately.

[fatmobile]

The cam will turn hard if the buckets are still in,..
 sooo I recommend removing those parts and rocking the cam like a teater totter to see if it will need to be bent straight and line bored before surfacing.
 Some rocking is probably OK,.. I don't have a number for when to line bore it.

[foxracer1]

Surfacing a head that is severly warped would cause the cam to rock in the saddles.

Thats what i thought.