Well with your power figure not changing, the fuel system stuff would have achieved nothing other than reliability/stability, and the 2.5" and airbox were probably flowing fine for what power you're making, no real surprise it didn't change.
I plan to go until I hit around 200-220kwatw, but it's a slow progression.
Btw I put the wideband on my car today (well, technically yesterday now), I'll post a graph soon but basically it was AFM hitting around 4.6v, injectors going close to 110%, AFRs levelling off at 12:1 up in the power. The stock fuel pressure regulator was actually running the car a bit rich by the looks of things, i dropped the pressure a bit and then had much nicer mixtures both in idle, cruise + on the power, odd. The top section of my stock fpr felt quite loose though and something inside it must have broken down or come loose.