Question is the car stock or running a 10 psi tune ? As tranny said get it up on the Dyno and see what's what. Post up the graphs if you want some feedback. Most guys on here use SCT flash tuners and have for years so heaps of knowledge. In terms of stock injectors it will come down to supporting hardware and the safety margin in the tune. My tip , do some searches as there is over a decade of tuning and modding threads on here so most questions have been already been discussed at length. Additionally, once you know what your base is decide where you wan't to go power wise. Step at a time is expensive in re-tunes , that said you don't wan't a billionty at the wheels if not used to big power.