Optional on the Patrol station-wagons as well as the tradie/farmer-oriented cab-chassis line-up, the ZD30 was not just a four-cylinder engine, but a much more modern take on the turbo-diesel engine ...

You said it yourself; it's tired, so I wouldn't fit a turbocharger without rebuilding the engine. You'd be asking for trouble to do it without doing the engine. While the ZD30 engine should have been ...