The complete kit plus parts machining and labor is far less than even a wrecked 450. I was planning on buying a kfx700v instead but ididnt have the funds. Im figuring i pay as i go at this point. As far as reliability your probably right but im hoping that 4ST are professional engine builders
Re: Looks like Im taking the plunge. 500cc BB 400EX
Figure this. Sell your 400ex, and use the money that you would put towards the motor. You should have enough to buy a nice 450R. You will have ATLEAST $1500 into the motor, and you could sell your current bike for seems atleast $1800-2000.