Ok so I've been toying for a long time with an sm build, this will be a long haul project as I'm strapped. For cash right now but in you opinion what would be the best, I have a street bike and a dirtbike so this will be mostly for a fool around ride and the occasional track day. So the requirements are it needs two wheels that's it haha put down what you think is the best engine and why? I'm looking all the way back to early 90's I was looking at an xr600, 525sx, xl600, crf450, yz250f, or even toying with the idea of my cr125. But I want opinions.