6in zone lift for 99-06 Silverado/Sierra 1500 4wd Quick Specs Front Lift Height: 6″ Front Lift Method: IFS System Rear Lift Height: 5″ Rear Lift Method: Block Kit Install Time Hrs: 8 Difficulty Level 1-5: 4 Wheel Size: 16 x 8 Back Spacing: 4.5″ Max Tire Size: 35 x 12.50 Wheel Size: 17 x 9 Back Spacing: 5″ Max Tire Size: 35 x 12.50 Wheel Size: 20 x 8 Back Spacing: 5.75″ Max Tire Size: 35 x 12.50