Full Fluid Service
Make it your priority to change the engine oil and filter, gearbox oil, IRD oil rear diff oil, swap out the old coolant for fresh and get the clutch and brake fluid changed too, new air filter and pollen filters and you are ready for dealing with any problems that come in the future from a known perspective.
I like to change oils and examine the old oils for metallic contamination, it enables you to look for high levels of yellow metals and any worrisome chunks that could indicate imminent failure of a component. I always advise the changing of brake fluids as a matter of course, how many people actually know that it should be done every 2 yrs? Not that many it seems and brake performance can be the difference between life and death, it don't cost much just time and a bit of patience.
Make sure you get the full Land Rover workshop manual for it and adhere to the schedules and you will have a brilliant motor for many years to come.