One more thing; I have heard that machine shops will stamp things into the front or back of a head after it has had machine work done. Is there any other reason a set of heads would have initials stamped in them? Do they stamp them if they just resurface them? When I was looking at mine yesterday I noticed that on both heads they have the letters "WAV" on them, and then one has a "36" on it near the "WAV". There is also a 6-10 number stamp on them too, but that looks factory while everything else is a poor job of trying to hit a stamp solid.
Any clue what the "WAV and "36" could be for? They didn't look ported or anything, but I wouldn't know the difference, I don't think.