TIG weld a AL head?

Is this Mazda head an OHC? If so, lay a straight edge along the cam saddles to test for warpage. If it's BENT, you have a new concern.
Not bent...ran a straight edge 7 ways to Sunday and no light under it. The small ridge actually cleaned up and I have the same amount of meat at the thinnest part that the head gasket has so it looks as if it eroded/wore right up to the fire ring then stopped. Im gonna run it and see what happens. Im attempting to use this head as its 109mm spec thickness so the valve timing wont be retarded. I believe they milled my old head way past maximum (.2mm!) and now I'm x degrees cam retarded. It just doesn't run like it used to before the head rebuild.