Even though the engine is as old as the hills it still proves to be one of the best out there. Landy drivers will pay top dollar for the engine alone for conversions to their trucks. Parts are still readily available and due to the age cheap as chips. All the parts that bolt onto it (altenator, turbo, steering pump) are identical to the Isuzu Trooper 3.1 of which there are many many being broken and laying in scrap yards accross the world. The 3.1 Trooper engine is pretty much the same, The only difference being the stroke length of the pistons. In fact my Trooper Mk.1 with the same engine (seeing as Isuzu developed the engine and Vauxhall just took it straight and dumped it into the Frontera) needed a new steering pump and replacement pulley for the altenator, both of which I removed from a 3.1 Trooper and bolted straight on. Working on them is easy as well as Isuzu blissfully engineered it with extra big bolts and rock solid parts. It is a rugged and powerful engine. Happly return 30-35 mpg as people say, and can cruise quite happily at 70mph all day long. Plenty of torque, enough to pull a house down. I have used mine to pull cars out of mud where they have buried themselves up to the belly with little effort proving the amount of grunt they have.
In short you cannot go wrong

As an aside. If for whatever reason the engine does die look for any Vauxhal Brava, Frontera and Isuzu Trooper, Wizrd, or Mu with a 2.8 and it will be identical. failing that if really desperate you could also pretty much straight swap a Vauxhall Monterey or Isuzu Trooper 3.1 engine in as it will be identical mounts and ancillaries. The only thing you might have to watch on the second option is the fuel pump where they opted for a semi electrictrical fule pump on automatic import versions, but your original mechanical fuel pump will just swap over. I also remember reading that they also used the 3.1 on some of the light Izusu trucks (as in proper trucks as opposed to our 4x4 trucks

)
The only thing I will warn you about is the standard thing to look for on any vehicle. mainly the condition of the chassis and crossmembers. Look for signs of corrosion and factor in getting the under side completely washed down, and it might pay you to get it all waxoyld or hammerited to protect it. When the summer comes have a weekend of fun lying underneath it with wire brush and cleaning everything up and giving the underside of the body a good scrub and then painting everything black. Its work like this that will make it last for years to come.
Good luck and enjoy your new potential Frontera ownership.