Torquemaster lower unit on an Evinrude H.O

Ok so Iv got a 2014 evinrude etec 200 ho with the m2 gear case and although it does have the dual water pickup as soon as the upper pickup break the surface water pressure falls off Iv changed out pick ups and everything and still can't get the motor up where I want it to be when running shallow... So my question is how hard would it be to stick a torquemaster lower unit on an etec? Not only do they have a better gear ratio than the m2 but also more durable and have a true low water pickup.