I very seldom change heads. I think nine out of ten might be too many- I have polished lots, replaced maybe three, and they were f***ed hard. Sometimes even a Volvo eats itself right to death. I have one in the shop right now that seized on the highway and from the appearance through the oil filler it is going to be a replace- when the cap is bright blue on the journal and there is aluminum galled out around the edges you are usually in big trouble. Usually someone who didn't know puts a new shiny cambelt on when it breaks, then it takes a lot of stress to break the new belt. It is getting pretty easy to find used heads from biodegraded junk.

It is a good idea to remove the second from front head bolt on the exhaust side when you get something that appears to have a poor maintainance history- I'm sure you know that Don, but its good advise for others.