I just bought an Echo CS-400 saw for my dad. This seems to be a nice little saw. Starts very easily and runs great. It is not a high end screamer, but seems to have plenty of torque, which brings me to my question. The factory safety chain has to go. I was going to refit it with 63PMC and see how much better that is, but before I do, I wanted to research other options. Specifically, has anyone here ever tried .325 narrow kerf on a CS-400? If so, how does it work, and how do I find the correct sprocket? I don't think that it would be hard to find the right bar, but don't know if there is a .325 sprocket that will fit the saw. Any advice?