Reading the other valve thread reminded me of another question I had. My dad says that he thinks that hardened valve seats were installed in the engine in my '48 Kaiser at some point. However he also thought that it had turn signals and it clearly did not. So is there a way that I can tell if they've been done? If they haven't, what would I expect to pay a machine shop to do it? And does the engine have to come out of the car to do it?