Moved thread in order to gain better chances for responses. Topic doesn't relate directly to electronic tuning of the ECM.
The answer to your question though, would be "stock fuel pressures". Electronic custom tuning is required to make 42 lb injectors work correctly with the Fox family of processors.
I am running around 42 or so vac off. I am hooking up a fuel pressure gauge in the car today, so I can see what it does with oost pressure. AS mentioned above, you really need a custom tune to take full advantage of the combo. I will be getting a tweecer soon.