Originally posted by Slunnie
The 4.7s have a thicker crown wheel to bring that gear closer to a smaller pinion. Is the smaller pinion stronger than the factory one, or a 4.1? I doubt, Rover ones are small to start with.

IMHO changing diff gears is the go, as it affects both low and high range. The aftermarket 4.1's are as strong as the 3.54's due to better materials. Mine were made by Dana for the Rover diff also.
Mine are from Kam, and the pinion is surposed to better made and stronger than the 3.5 pinion
Here is a pic of it