I would see if anyone makes seals out of some "Rubber" material rather than the teflon or plastic of the ebay seals. They will tolerate a lot more in terms of loose valves etc. Not sure if the 230's do it but the M130 2.8 engine has a tendency to have the valve guide to slip in the head casting so rather than the valve riding in the valve guide the guide moves up and down in the head along with the guide. I replaced my seals before Joe Alexander pointed me to the real problem.