I have an '09 3500 SRW 4x4 that is in need of new rear shocks. Anyone know of an aftermarket brand that will fit? I made the mistake thinking that these trucks used the shocks from regular pickup trucks and ordered a pair of Bilstein 24-191203 and they don't fix. The upper mounting bolt is larger (16mm) vs the lower (14mm). Regular pickup trucks shocks have the same size top & bottom. Any ideas if you've replaced yours, what did you use?