Exactly, and one point I'd like to make about shimming a pulley like for a water pump.
Most think shimming is putting washers under the pulley and how hokey that is to do, but that's not the only (at home) way of doing it.
I take a piece of metal the thickness I need and use a 4" grinder with a cutting wheel to get my general shape.
Then I'll use a grinding disc to finish the shape (a circle in this case) and drill it for the pump shaft and bolt holes.
Touch it up with a flap disc, paint it if I feel the need and there ya go, a nice solid and flat spacer.
