As far as I have seen, the YFZ is a DAMN good motor.. Low to mid 40's in hp right out of the box, and a really broad torque curve. Plus, the carburetor is still more pleasing to me than the FI CRF450. I don't want to deal with that much electronics.

On the suspension, I still believe that its not the arms, spindles and shocks that are the problem on the stock LT, its the steering geometry and width of the frame. Narrow the frame, and use +3 or even build +4 arms and make the proper tabs for the knuckles to correct the Ackerman. Its going to work plenty sweet!