thx DynoRay thx helps I will be porting the head and adding a 11:1 piston med cam will it help for that mod??? What will I get out of just doing that do you know??? I'm used to working on my banshee this 400ex is a different animal

 

Hey Huskerjim, you should make a solid 35 hp. As I said earlier, the porting and valve job are CRITICAL to make more then 37-38hp. I would suggest the Hotcam stg2 installed straight up for trail riding and retarded 4 deg for trail/race.
You should make the 37-38 mark with a decent porting and valve job.
Happy roosting