I've got to do something with mine, it was off a running motor, years ago, but it's stuff as hell and oily all over, and probobly has 400K on it. Thought it did work quietly.
I can get a kit and do the work, am I asking for grief? I saw a couple really good writeups online.
You can do it but for what the xs place charges it's not really worth it
I did my old one and it was fine. However, you obviously cannot balance it. You can just mark the wheels and line them up afterwards, but the chances of them still being in balance after 300k miles is pretty slim.