I owned a Dynojet for 6+ years with thousands of runs performed. While we pretty much always ran cars in whatever gear was 1:1, I would not call the HP figures inaccurate when/if running a car in a different gear then what would be 1:1.
The current dyno we use to tune our projects is a Dyno Dynamics AWD with load/eddie current. Just to verify information, we asked him(the tuner) today about HP numbers on his dyno in different gears. His reply was it doesn't make that much of a difference.
That's some collection of parts. Please let us all know when it makes the power and if possible let us all know details. Good luck.
Looks like good power, but still less then the 552whp he is asking about.