2002 Honda 400ex rebuild questions
 

Ok so i bought my 4 wheeler a year or so ago for a trail riding trip with some friends and did general tune up on it, ran fine while I was there, but I'm deciding to do a rebuild on the top end. My friend wheels and deals stuff all the time and gave me a stage 2 hot cam for a weld job i'd done for him, so I'm wondering what all i need for the stage 2 to be compatible.
it's just stock 400ex right now but i may be willing to get a big bore kit but I want mainly a top end rebuild. All help is appreciated