I have been wondering if aladyneing the surface might help.  Annodizing kinda
gives the surface a rough texture from what I have seen and you can't use that
on a head (must be smooth).  However aladyning (which is done on aircraft
aluminum skin to protect it from corrosion) is just a chemical treatment and
does not alter the surface but merely coats it with a corrosive preventing
flim.  My only wonder is if the head gasket sealer will stick to it.
Ken Wilford
John 3:16