[CivicSpoon]

An intake manifold and a bigger throttle body aren't going to do much for you, until you get some real modifications. The stock B16A intake manifold is the best one to have for a street driven car, anything else will shift your powerband into higher RPMS. the bigger throttle body won't do anything for you, no real gains or losses from it. Neither modification is going to help you run leaner either. The stock ECU will compensate more fuel (to an extent) when you do mods that increase the air flow into the engine, so trying to add more isn't going to help any. You should do a tune-up, as well as check your O2 sensor if you're really running too lean. Why 9,000 RPMS? Unless you increase your compression ratio and get some pretty aggressive cams, you're not going to be making power up that high. Revving higher doesn't mean you're car is moving faster or that you're making more power, it does however increase stress on engine internals.

Personally I would stay away from Brian Crower stuff, at the very least their valves and valvetrain. I know someone who had their cams, valves, and full valvetrain, who did not have a good experience. One of his BC valves broke clean off, because of a defect. They did give him new valves, valve springs, and retainers, but his head was a total loss. But I've also see threads on Honda-Tech about their cams not being machined enough (or properly), and causing clearance issues; essentially grinding away the cam and parts of the head.