Set up a dial indicator to measure the height of the plate before and after applying the specified torque. If it's out of spec, you have to change it anyway.
Jeff, metal shims with thin paper gaskets are the best and predictable if you can get the correct shim size. This is much more precise and easier to measure. The for and aft travel of the shaft while running is minimal but it will drift forward. If it's too tight it will rub against the stop. If the stop distance is too great it could put pressure on the intermediate gear causing premature wear. A thick paper gasket is trial and error even with a dial indicator there can be some measurement deviation. If you can get within range you should be fine
