If you can do a cam belt you can do a camshaft, they are simple as far as internals go, Price ranges from £160 to £500 It makes it sound nice, makes it go better but its all about shifting the power, it doesn't make power as such, it will take for eg.. 10hp from 2000 rpm and give it to 4000 rpm, depending on the type you fit. Thats about as much as i know about uprated shafts.