The differential was fitted with solid derlin bushings. Ordered from company on e-Bay for under $40. The fit is extremely tight. Emphasis EXTREMELY. I would recommend for anyone doing this, since this piece is heavy and awkward, use some heat and block of wood with sledge. I used a 2 or 3 pound sledge, with a 4x4 block...with some aggressive persuasion, and several rests, finally got them seated square. The ride with them, to me, was not as severe as some stories told. I guess if you are looking for some modern touring sedan quiet lexus feel, this isn't going to cut the mustard. But, for a sure grip, pavement ripping, no give feel.. these make the car hook hard, but rear skated sideways a few times quickly.