Sayers

Hi, I am currently looking to buy a 2002 XKR 4.0 SC, however ive read horror stories regarding Nikisil coatings and dodgy timing guides and chains. I see a lot of XKr;s for sale with mileage from 60 K to 130 K , surely these cars are now proven as good ?? Anyhoo. is their a guide or method I can use to check that a Nikisil type engine is okay, ? and if so, what is the expected mileage I could expect to get out of a well cared for unit ? Thanks