I have a 78 XS650 that I have been rebuilding for a few years. Engine runs and frame is in good shape, everything else I have been slowly replacing, including the wiring harness, master cylinders, coils, etc. I am a little anal about replacing things that may not need replacing, after all some of these components are over 30 years old. My son and I have been debating about the need to replace the gaskets and seals in the engine. I say they need to be done, he says no need since they do not leak. I plan on riding this thing a lot once it's up and running so want to replace everything to avoid aother tear down in the future. What say you guys?