hey. Im looking to drop a crf450 motor in a 400ex chassi. I know you have to do many mods. Im looking for any tips on what to do or watch out for when i do this. Can you hook up stock 400ex headlights to the crf motor? I gather you need a crf exaust for this mod? does any one know of a conversion kit for this swap? I know they make 1 for the 250x 350x conversion. thanks sam-