GMC Sierra 2005 Owner's Manual page 473

If your vehicle has single rear wheels and the tread
design for your front tires is the same as your rear tires,
use the rotation pattern shown here when rotating
your tires. If your vehicle is an SS model, the spare tire
is not designed to be used in the tire rotation.
If your vehicle has dual rear wheels and the tread
design for your front tires is the same as your rear tires,
always use one of the correct rotation patterns shown
here when rotating your tires.
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