Since you are running it in a Land Rover, are you going to be using it for "off road" playing - mud, sand, rock, etc.? If so, take a look at the NV 4500 and similar transmissions; they'll handle the torque, and give you the gears for offroading, too. Advance Adapters is one manufacturer and supplier of these boxes, as well as a whole passel of other gear related stuff.

http://www.advanceadapters.com/