I'm doing a complete rebuild on my 01 426. Got the valve seats cut and porting done by Gorr, and am getting ready to put in new stock Ti valves, new springs, keepers, etc. This to go along with a new crank and 13.5:1 piston. In looking at the Yamaha shop manual section dealing with replacing the valves, it says to lap them with coarse, then fine lapping compound. I've read several posts about Ti valves and the Titanium Nitride (or whatever other hardened coating they put on 'em) that say to not lap the valves. Makes sense. What say you, TT experts? Lap or not? Anyone care to share?