This winter I will be rebuilding the top end in my 2012 KX450F (actually, a very reputable guy that does mx engine rebuilds will be doing it for me...). He is suggesting using either OEM, Pro-X or Vertex components, but does not like Wiseco. I tend to think that is a builder's preference, or frankly, where he might get the best pricing or whatever. He said that as part of the top end rebuild process, he will cut the seats, hone the cylinder, new camchain, set shims, and reassemble. If the tappets, seats or guides look worn, those will have to be addressed, but probably not likely. The bike has run spotless for 50+ hours, but I crank on it pretty good and am doing this for preventative maintenance. My thought is to just stick with OEM stuff and be done with it -- the stock bike has plenty of power and runs great. However, I just have to put it out there and see what others might recommend from experience. I don't necessarily want to go to a higher compression piston, simply because I think that adds heat (higher engine temp) and I really don't think it is necessary. I just figured, since the top end will be apart, I want to explore a few options and see what kinds of suggestions anyone might have.