I bottomed out a Bilstein 7100 series shock. Rebuild kits have the o-rings and internal parts but I need a new end cap. Found this # (800) 537-1085 for Bilstein America but after 1.5hrs on hold I gave up. I cant find any diagrams with part numbers. I would also like to get some stiffer valving. AK7112SB is the shock I am working on.