RST-G : I honestly believe you should get over the 400bhp mark with your GT30, BD10's, Low Comp, and a good modified head. As mentioned above.....with grey injectors, they're on the limit at around 430bhp, and will start running lean underload at high rpm (Basically they're maxed out to their limit for supplying enough fuel at the sort of boost you'll need for 430bhp). Too Lean to risk melting an engine, and not worth the risk. Put in a set of Siemens Blacks, and you should get the 430bhp.assuming you have the right ancillaries....Big Intercooler, Group A Fuel Pump, etc.