I have an IH 504D that I am thinking about rebuilding. Over the last couple years it has lost lots of power and started smoking a lot. Now it will start, but that's about it. I'm afraid to even move it from the barn for fear of not being able to drive it back in. I'm just wondering how difficult a rebuild will be on this. Can it be done in-frame or does the whole motor have to come out? If I get the rebuild kit, is there still any machining and additional work that has to be done by a professional or is this a doable job for the do it yourselfer? Any advice would be great. Thanks