My crankshafts always stick out past the outer clutch-bell bearing.

Well...okay, I think I have one that doesn't. Anyway it's good to have a variety of shim sizes on-hand to deal with the extremely common situation where the crankshaft is a fraction of a millimeter too long or too short. I use Kyosho shims because they come in a wide variety of Metric sizes, and three different thicknesses per pack.