Chevrolet 2008 Silverado 1500 Pickup Owner's Manual page 508

Front Position - 1500 Models Front Position - All Other Models
4. Position the jack under the vehicle as shown. If the
flat tire is on the front of the vehicle (1500 Model
vehicles), position the jack under the bracket
attached to the vehicle's frame, behind the flat tire.
If the flat tire is on the front of the vehicle
(all other models), position the jack on the frame
behind the flat tire.
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