I need to replace the head gasket on my daughter's '91 240. I have a head in my basement that I was going to install. I want to get it checked out prior to installing it. However, I'm not sure what I should have done to it. I know that the lash on one of the valves was way off thus prompting me to get it looked over. I'm thinking that I only need the head to go for another 100k miles (it has around 210k miles on it already) Any recommendations as to what I should have checked out?

Also, can anyone recommend a machine shop in NW suburbs of Chicago that is familiar with these engines?