You can put 50hp carbs and a 50hp tuner or you can look at hydro tec web site. They mod the stock tuner. You can shave the head and add some fiber reeds. Those are the easiest mods for a noticeable gain. I think hydro tec offers a package deal for head, reeds, big bore carbs gaskets and tuner for around $990. Suppose to be around 20hp gain. Don't really think you'd gain that much but a stock 50hp tuner and carbs would be a lot cheaper and still bump you up to 50hp at the powerhead plus a machine shop should be able to shave your head for less then $50.