We’ve prepped our Mitsubishi Montero to handle journeys of a several hundred miles or so. It’s interesting to see how people who travel tens of thousands of miles prep theirs. The couple behind the site Land Cruising Adventure have a page devoted to the modifications on their Land Cruiser BJ45. It makes for informed reading.

Land Cruising Adventure, Mods page
Land Cruising Adventure, Meet the Land Cruiser page