2011-2019 Chevy Silverado / GMC Sierra 2500/3500 HD 2WD/4WD2'' Rear Block Kit. PN 9-9005Rugged Off Road 2Inch rear block kit for 2011-2019 Chevy Silverado / GMC Sierra 2500/3500 HD 2wd and 4wd trucks. Comes complete with vehicle specific u-bolts and hardware. Adds a nice rake for towing or hauling additional weight in the bed. Easy to install. Does not require any permanent modifications. STOP 1988-1998 Chevy Silverado / GMC Sierra 15002WD/4WD1'' Rear Block Kit. PN 9-9007Rugged Off Road 1 Inch rear block kit for 1988-1998 Chevy Silverado / GMC Sierra 15002wd and 4wd trucks. Comes complete with vehicle specific u-bolts and hardware. Adds a nice rake for towing or hauling additional weight in the bed. Easy to install. Does not require any permanent modifications.