Not when the car is dynoed in the 1:1 ratio, which is 5th gear. The car makes what it is supposed to, around 415bhp. If this motor is SAE certified, like the LS3 motor for example, the motor makes 415hp, +/- 1%. It might not be SAE certified, don't know. Regardless, dyno appropriately and the car makes what it is supposed to. It doesn't really matter as the 5.0 runs hard and fast at the track regardless of a dyno number.
The 5.0 power jump from the year before is very big and the motor is a dream IMO. When Chevy went from the LS2 to the LS3 motor in the Vette, it was 36bhp more with an extra .2 liters. The LS3's heads and intake manifold are superior to the LS2. Yet swap the heads/intake out on the LS2 and the hp/tq is very close. Stock quarter mile times favor the LS3 by a small margin but bolt-on vs bolt-on, the LS2 is still champ. Not worth going from one to the other I think. But the 5.0 is just such a tremendous jump over the previous model, I can see where I might consider switching if I had the ability financially (assuming I had one in the first place of course). That's just me though, opinions will vary