I was wondering is there any Final Drive options from the factory, that you can choose from at time of purchase?

From what I found from several sites show that the Infiniti G35 from 2003 to 2006 has a 3.357 final drive. But this thread here...
https://g35driver.com/forums/drivetr...explained.html
shows several different Final Drives. I am using Forza Motorsports 4 to kind of drive the final Drive ratios and see my MPH vs RPM ingame to compare. At first I though the website I visited was wrong, or considered that the game had a programming flaw in it, and wasn't accurately showing the RPM vs MPH relation at these gear ratios.

Because to get the speeds my car travels at, at the specified speeds the RPMs only match up with a 4.083 final drive. Was it swapped post factory? Or is it an optional swap at factory?

 

There are no optional FD from the dealer.

Used to be 6mt 3.5FD, 5AT 3.3 now I think they all have 3.7FDs.

Aftermarket option 3.9FD or 4.08 (which is out of a Frontier)