Only have 460,000km on my old NJ with the same motor. But it does use water so I think it does have a cracked head. Still does what I need though (bush pig fire wood tractor).
Have had ours for 20 years. Have always heard rumours of cracked heads, but never come across any who has had an issue. I put the rumours in the bucket as the stories about Pajeros have crap gearboxes. But the gearbox issues relate to the Sigma derived gearbox in the mid 80's Pajeros behind the first petrol 4 cylinder models. Since about late 80's gearboxes have been really good, and about twice the size.
The NM model 2002 would be the very last of the 2.8s before the 3.2L was introduced.
The 3.2L to about late 2006 (pre common rail injection model) has expensive issues.
Would be a good solid car, but make sure has been looked after. Like a car of any brand, at 18 years old it could have all sorts of gremlins hiding.
The 2.8L was introduced in the NJ in about 1993, so had been well developed (or outdated if you are a pessimist) by 2002.
Drive line is virtually bullet proof behind the later 3.2L with nearly 30 to 40% more power and torque.
He would be able to build it up and then transfer all the good bits onto a 2012 (for example) model down the track.
Everyone will say it lacks wheel travel due to IRS at both ends, but that just means you learn how to drive instead of just relying on sloppy live axle suspension
Not affected by the current airbag recalls.
Our No. 3 son has a 2000 3.5L V6 NL with only about 200,000km on the clock. Goes really good, but still prefers to drive our lazy, worn out 2.8L slug