Kind of splitting hairs, but the spec is 270 CC/min @ 43 psi. I have RC recalibrate every race season, and they typically only measure 255 to 267 prior to clean / balance. It doesn't take much to throw them off.
BTW, that works out to about 37 HP per injector at an 80% duty cycle (maxed out). So you can only get 3x37 = 300 hp out of these injectors at 43 psi. This of course assumes you have a pump that can supply the fuel and a motor that can burn it. Thats why an adjustable regulator is handy.