Why change to hydraulic unless your mechanical is giving you problems? If it ain't broke, don't fix it... that kind of thing. To each his own, but I like the feedback I get through mechanical steering. That being said, if my mechanical steering goes south, I'd replace it with hydraulic. My 225 was a 2.4 carb motor, so your 2.5 should be stronger. Ballast goes in the port side as far back as you can get it. Depends on your weight, but you'll just have to experiement with it. Put everything you can on the port side before you start adding ballast.