Exactly those mods can give you roughly 10HP...I mena yes there are mods you can do to give you more HP other than that but it's a great starting point unless you have an endless $ supply to do what you want or get a turbro or something of that nature..
it's not worth getting a header if you are goin to get a turbo or swap but 9 times out of 10 you can still use the intake and exhaust..
Hope this helps a little more...
