thought i mite give u my 2c on injector size, I have a standard RB25det, Z32 afm, pwr fc, Vg30 hi flo 040 fuel pump, and went for the 555cc injectors, runs 15lbs all day every day, has 250rwkw, this is not pushing the limits, 555cc handle the job nicely with more room to move if need be. was going to go bigger but not needed, what are u looking at kicking out power wise?