Hi new to the forum im rebuilding my 400ex. Doing a je 426 13:1 comp piston, webcam 479 grind with +1 valves im having the head work done by ftz. Also i will i am running the sparks bigcore exhaust. I have an 05 450r carb i plan on running on it and i want to make sure my jetting is atleast close for breaking it in right now it has a 48 pilot and a 175 main and im at 400 above sea level any suggestions would be appreciated