Give it some time and then take what they average at the track (MPH) and that will give you a better idea of the power they make.
My 03 Cobra made 426rwhp and went 121 in the heat @almost 3700#. So if Dynos are correct then all these ZL!s that are making over 510 should be going about 125?
Dynos are cool and they have there purpose but I don't think they are accurate as far as giving numbers.