Re: Can a shorty slip-on ruin valves?
Lean running causes a few gradual wear issues that do come prematurely. It varies. I've seen holes burned through pistons many times, and have done many valve jobs. Some takes weeks, some take years. Ride it another year and see if you have valve wear or a hole in the piston, and if it's still good, go another year, and so forth until you do burn a valve. It just takes time when running lean. If you run it hard at sustained high speed, you can speed up the process if you like. If you want to see the difference, try a power commander, it might run even better than great. I hear this comment every day.
Never have I seen one customer say "Oh this sucks now, take that power commander off, I never needed it." They all go, "Wow, what a difference, it's so much more responsive." Support your local repair shop, one way, or the other. People screw hookers every day and wonder when they'll get HIV.