you have a few options depending on where ya live. Bergen Diesel (203-747-1869), he's out of Middlefield, does great work. Down towards NY side, in Stratford you have Champion transmission and diesel performance. On the RI side, there's the Diesel Shop LLC in New London, in Chaplin there's Street Diesel Performance, and in Waterbury you have New England Performance Products. Those are the few folks I would trust my truck with, I've had Bergen diesel work my truck before and he's great and do whatever it takes to get it don right.