 The gearbox has shown to hold more power than the factory stated quite reliably.That being said, a lower geared final drive helps eliminate excessive stress on the gears; thus the 3.82 FD (final drive) is weaker than the 4.05 and the now hard to source 4.45 gearset is the strongest.The transmission can still break, especially with a fast spooling turbo to create a low end boost spike.