Its all going to depend on the rest of the setup. If the turbo you choose only flows enough air to make 350 whp then having things like an intake manifold could be important. Will you see gains from a larger manifold, most likely, will you not be able to make 350 whp because of the manifold, depends on the whole setup but no. My advise would be to do some more research if you are taking on this project yourself. One thing you will learn from experience is it takes more than the correct parts to make a honda make upwards of 250 whp.
