well when you start getting into that much boost the intake becomes less important, i do not think upgrading that intake will net much more, its more about matching your parts at this stage and having the right tune, i dont see what cam you have, when you start getting into that much hp it comes down to compression,cam,head combo's, you are probably at your limit with that combo, if you want more bigger heads custom cam and more boost are next., its easy to go from 400-500 hp but a whole lot harder to go from 500-600