I'm betting this engine has never been fired. And if that's true, then he's not going to find a lick of carbon in that head. If I were an engine builder, I wouldn't sell an engine that I had completely built, but not broken in. That's just asking for trouble. The next thread we get will be
"the rings won't seat, I've got no compression, the lobes are making a funny whacking noise, and there's shiny stuff in the oil."