My T4.1 is a T4.1 with plastic B44 zero degree rear hubs, a shaved u-brace, VTS, and Dubro 2263 heavy duty captured inside rear camber links. I prefer the "A" hubs over the "C" hubs because the truck really needs a high roll center. The higher rear roll center is the result of testing and tuning across very tacky and dry conditions and cannot be achieved without "A" hubs. The rear of the T4.1 is VERY sensitive to ride height -- anything higher than 28mm in the rear on our indoor track makes my truck difficult to drive.