The 3.0L by all accounts is pretty bomb proof with some reliable high mileage examples about.
There are several threads on this Forum if you look for them, but the general consensus seems to be that total mileage can be less important than type of mileage and how the car's been driven
(i.e. 60,000 careful motorway miles is probably preferable than 40,000 miles in the city and regular out of town thrashing) :thumbsdown: