American Automotive Silverado Sierra 2WD 4WD 1-2" Rear Lift U Bolts 4PCS 12.5" Extra Long OEM Material FITMENT: Square bend to clamp 2.5" wide leaf springs on 1999 - 2007 'Classic' Silverado Sierra 1500 2WD 4WD; Does not fit spring overload models CONTENTS: 4 certified carbon steel square leaf spring axle u-bolts. Specs are 12 Inch Length, 2.5 Inch Width, 9/16 Inch Thread Pitch with 5" thread can be cut down to fit other applications and grade 8 hi-nuts and security spring washers. TECHNICAL NOTES: Retighten u-bolts after the first 500 miles; Minor settling from new or repaired springs can cause a reduction in clamp force BENEFITS: American leaf spring axle u-bolts are designed for maximum u bolt clamp and embody extreme strength; These ubolts provide an even distribution of pressure to protect against premature spring failure and unwanted movement; Made of OEM factory material American u bolts maintain original vehicle handling characteristics and are guaranteed for life NOTE: U bolt color may vary