Might want to research this a little. I had a friend who was service manager at a Ford truck dealership who bought one of the first of the Isuzu turbo diesel pick ups. I am not sure about the mileage but I think it was at around 60,000, he broke a connecting rod. He contacted Isuzu amd learned that the early production turbo engines were built with the same internal components that were in the non turbo models. Isuzu then upgraded some internal parts, including the rods, and solved the durability problem. Isuzu went on to issue an extended warranty to him and replaced his engine with the improved version.
Someone should be able to determine an engine number that would be the improved version as opposed to the earlier production. He might never have a problem, but having the stronger engine would be better. I understand that Isuzu began using the improved version in both the turbo version and the non turbo version, but I don't know exactly when this change was made.
I had a 1982 Isuzu pick up with the diesel and it was a very reliable little truck.