GMC 1999 Sierra 1500 Pickup Owner's Manual page 262

Problenrs on the Road
Jack Storage
Your jack and wheel ratchet are behind the passenger seat. Turn. the wing
nut counterclockwise and remove the cover if there is one.
Spare Tire
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i
K2517
Your spare tire is either underneath the rear of the vehicle, or mounted to the
inside of the bed on the driver's side.
If
you have a chassis cab, refer to the
information from the body supplier/installer.
The spare tire is a full size tire, like the other tires' on your vehicle.
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