What injectors do you have? Standard injectors are only good for about 250-260rwkw max. Standard fuel pump is good for high 200's. So if you put a set of 42lb injectors in you can go maybe about 280rwkw. High flow cat, xforce cat back, 42lb injectors, F6 or monza intercooler and you should get ~280-290rwkw with a custom tune.