ok guys so i want some more power im running the following engine mods:

ej207 with forged internals
Autronic PnP ECU with Anti-Lag & Rotational Idle
IHI VF34 Turbo
Trust Front Mount Intercooler
MMS 3" butler Exhaust
MMS Up-Pipe
High Performance Bosch Fuel Pump
BPM silicon turbo inlet
Cats Removed
Apexi C.A.I
AFM removed

i recently had the tune cleaned up by sean @ allstar garage and the car pulls pretty hard now as it never realy had a retune since it had been rebuilt the car made 275hp @ 1.3bar i will post up a dyno graph soon... the boost is a constant curve and doesnt drop off at all so pretty much what im saying is boost is just constant all the way to redline .... i have had the car a while now and the car is just feeling like an excel because im used to it what can i do to break the 300 mark and achieve around the 320-350hp mark

my question is headers, turbo, injectors, tune?

kind regards