I've just pulled my 02 WR426 down following a gearbox failure and am going to adjust the valves while the motor's out. Can I use the shims from a WR250 in my 426? Also, two of of the inlet measurements are right on the minimum at 0.1mm, but one is 0.12mm According to the manual, shims come in .05 increments. Now this is not a problem in relation to the first two valves, but if I go up one shim size on the 0.12mm clearance, that will take me to 0.17. The book gives between 0.1 and 0.15 as the recommended range. Do I leave the third valve or change it to 0.17?