All this talk of the magical TD42, the most overated engine of all time.
The 62 Series Landcruiser 12HT was more advanced then the shitty TD42.
Direct injection for starters and didn't have a tendency to overheat like the TD42's are prone for.
Throw 15 grand at a ZD30 and see how it goes, will probably still leave a TD42 with 15 grand spent on it for dead.
You will hear bullshit stories of TD42's doing 1 million km's.
Never seen any proof though, its all just claims.
My choice would be the TB48DE.
Ill rather put 15 grand into a Duramax install then a TD42 that will always be shit on fuel and still overheat on long hills.
The ZD30Di with a few mods will go the distance, takes the turbo control away from the ECU and half your worries are fixed.