As the title says I'm wondering if it's possible to swap out the 3TNE99 36 hp Yanmar that's in my tractor now for the 4TNE88 47 hp Yanmar. I have found quite a few low hour engines near me for pretty cheap and I was wondering if the swap were possible. The big problem that I find is that I'm needing some more power than the tractor can put out right now. I looked at some used 5320 and similar JD machines. The problem then would be getting into some of the tight work areas that the 4400 excels at. I guess the other question is can I get more power out of the 3TNE99 (tweaking the IP is the first thing that comes to mind)? Obviously the easiest way to get more power is more fuel (injectors, delivery valves etc..) but then she'll run hotter and with no turbo I don't think it's a great idea. I suppose this is partially some frustration because I do ask a lot from this machine. Heck maybe I should start looking for a skidsteer....then the lawns would look like a war zone