The torque master gear case is the standard gear case on a Mercury 200,225 and 250 Pro XS. Mercury does make a gear case with 1.62 gears that you can put on a 225 threw 250 but that is for your ligher go fast hulls such as an Allision, Bullett boats. It is not worth a flip on a heavy boat such as a Ranger, Triton or any other of your heavy boats.