FWIW the 7.3l Powerstroke in the Ford was an International V8 diesel, not Isuzu. GM puts the Isuzu diesels in their trucks now because the 6.2/6.5 was so problematic. The 7.3 was a pretty good engine, it originally started out as the 6.9l in ~1978:
http://www.dieselpowermag.com/tech/ford/0703dp_international_diesel_engine/index.html
Nice engine but ther is no practical way to put one in a LR.