Here are some pics of my valves from my 02 426. I am giving the top end a refreshening and wanted to inspect the valves while I replace the piston (which had no wear). I measured the valve seat width, stem O.D. and both measured like new. The manual gives runout as well as "new" specs and all 5 were very close to "new" specs and nowhere near runout. The seat width does look a little bigger in the pics due to lighting however. The tips are multicolored telling me that some of the coating has worn but not all. I have never had to adjust any of these and have never had any hard starting problems. The clearance all measured within spec although it was closer to minimum spec rather than in the middle. Tell me what you would do.