The great thing about digital flight manuals is that they make things like this easy to prove, unfortunately it isnt for the Gulfstream
Change Gross Speed
DEG Grad. KIAS
------- ----- -----
Screen Height .0 2.7 153.5
Gear-Up .0 2.9 153.5
Level-Off .0 2.7 153.5
Start Final Climb .0 3.9 225.0
But if we increase the V2 by 10 knots without changing anything else....
Change Gross Speed
DEG Grad. KIAS
------- ----- -----
Screen Height .0 3.2 165.0
Gear-Up .0 3.4 165.0
Level-Off .0 3.3 165.0
Start Final Climb .0 3.9 225.0
You can see that with the higher V2 the climb gradient increases, the figures above are single engine AFM data, but the same should apply for all engine performance.
It will all depend on which noise monitor he is trying to avoid
Mutt