Id hope he has, as he will need approx 100psi(6.89 bar) for the injectors to cope......
It that the base FP?..
It will deffo be running a very high injector duty, but i think your calculation is off abit...
So the 460cc injectors at 100% duty at 3 bar FP will be good for approx. 368hp
460 / 5 x 4 injectors.
3 bar base FP + boost of 1.7 bar = total FP of 4.7 bar.
At 80% duty they will flow approx. 295hp So i think a base FP of around 4 bar will do it plus the boost 1.7 bar so full boost FP = 5.7bar.
An injector upgrade would be good so not to run the components on their limits and high FP is bad for the fuel pump.