So I plan on getting my turbo rebuilt in to a ko4 hybrid. I am currently fitting new rods and a Fmic, as well as a tip, down pipe, and a new manifold. But was wondering what is the best air filter for money whilst looking as standard as possible. Would it be worth changing the valves in the cylinder head. What manifold to got for and is there any point in upgrading the injectors? If so to what size? And what dyno figures has any one else with the same set up produced thanks?