Dyno numbers are good to give you a rough idea of what sort of power your engine is making and, of course, as a tuning tool.
What really matters though is what power (torque) your car is putting to the ground, as a dyno is not calibrated to measure that (dynos are calibrated to show a 1:1 ratio). You actually make 22% more torque in 3rd gear and 27% more torque in 4th gear (throughout the full rev range, not just peak), than if you were using your stock transmission.
To put this into perspective, the 279lbft peak you are making on your car just now is equal to a car that is making 354lbft peak that is running on a stock transmission.
Just some food for thought, as not everyone understands the torque multiplication aspect of changing your gears