Hello from Brisbane.
The various outlets for Roamerdrives (e.g. British Offload) sell a finned alloy cover plate for ~$100 that is intended to allow the transfer case oil to run a little cooler than normal.
The added bonus is that this unit is supposedly less prone to distorting than the original steel bolted to alloy arrangement, and hence less prone to leaking. Might be worth investigating - I am sure there will be people out there with them fitted to their trucks.
Cheers

