Ok I did it, I went and bought a KX 450 f with full intentions of doing the conversion. This may make people want to kick my butt . As I was a die hard 2 stroke rider, especially my 2001 KX 500. After taking it to the track and then some nice single track and short sandwash desert riding I have to say that I love the 450 f . I dont see me doing any kind of swap unless I blow up the 450 engine. I love my 500 dont get me wrong, On rides or races when I can open it up thier isnt anything better. But the 450 gives me much bettr traction, it feels 50 ponds lighter very easy to ride and just a fun bike to ride, So for now I will keep the 500 and the 450 f seems like the best of two worlds.