I was under the impression that the valve clearance for a bucket and shim set up got tighter over time due to valve stretch. On my 2006, I went from .009" on the Exhaust to .010" for both exhaust valves in about a year with 50 miles or so every other weekend. The intake on one stayed the same at .0055", one went from .0055" to .008", but the center one went from .0055" to ,010". Spec is .00039 to .00059. Strange thing is, I measured the gaps, then measured the shims to see what I needed. I was able to swap two, and needed to buy two. When I re-assembled, 3 of those measured as expected, but the the center Intake, which shim was measured at .074" and replaced with a .079" still had a measured gap of .008", which is .002" out of spec. Pretty weird that the one valve that was almost .005" out of spec, did not work out when I replaced the shim wit one that was .005" thicker, going from a 185 (.074") to a 200 (.079"). Anything I should be looking for on this valve that I may be missing?