Alex is right I did a complete top end on mine Sunday with a stage 1 hot cam no modifying to the head u can use stock components for best results exhaust and aftermarket filter are a must but a basic port and polish to the head will maximize out come with the other components it takes no time to install the cam bearing can be a pain but Yamahauler has a trick to it that works well if u talk to him before starting the project if valve noise is a concern hd springs will quiet it down a bit don't use the cam given clearances for the valves do .004 on the exhaust and intake it will give u best performance with out the clatter