I know there is a thread around for this somewhere, but can't find it. I do, however, have the photos bookmarked. This is a pictoral for a '10 and up valve lash check. There is a little more to it than this if you have to change shims. For example, if your shim (semi-sphere) measures as it should and your clearance is off then something else is worn and you will need a new shim of a different size to change the gap appropriately. If the shim does not measure as it should and the gap is not correct, then there is the possibility that you need a new shim of the same size to take up the gap. Provided, of course, the valve lash change needed = difference between actual shim size and spec'd size.