ReadyLift offers model-specific wheel spacers for 07-UP Chevy Silverado and GMC Sierra 1500 6-lug trucks. Precision CNC-machined from 6061-T6 billet aluminum for maximum strength and longevity the ReadyLift 10-3485 wheel spacers are 7/8" thick and include pressed in 14mm factory style studs. These new wheel spacers are designed for use with the ReadyLift 69-3485 69-3285 69-3295 and 69-3495 4" SST Lift Kit when running the factory wheels. Wheel spacers are required when using the factory GM wheels and the 4" kit to properly space the factory wheel away from the suspension. Will only work with factory GM wheels which have the "pockets" in the back side of the wheel next to the lug holes. Will NOT work with factory steel wheels. Some 2017 and newer wheels with the "pockets" the pocket are not as deep as previous wheels and may required slight trimming of the factory wheel studs.   Caution- make sure the factory lugs fit into the wheel pockets without making contact with the wheel " the adapter must fit flush with the wheel. Each wheel spacer is both hub centric and wheel centric to ensure the absolute perfect fit with your hub and wheel. You will not find a stronger wheel spacer in this size anywhere on the market. When installed the 10-3485 wheel spacer will place the outer wheel lip in line with the fender. The wheels WILL NOT stick out using this spacer. Can be used on '99-07 GM 1500 trucks if required for the individual application and if the factory wheels or the aftermarket wheels being used on the 99-07 Classic body style truck have the factory pockets cast into the back side of the wheel next to the lug holes. Sold as Pairs. (two wheel spacers) Quantity 1 = one pair. For use with GM factory wheels that have the "pockets" next to the lug holes.