It involves a ton of work from what I have seen. It would also reguire stronger driveline parts to deal with the torque. It's a cummins 4bt engine.
Go here to learn more.
http://www.4btswaps.com/forum/index.php
I think one would be sweet.
it would be awesome to have, but with the price of diesel fuel right now, it wouldn't be practical. the last i saw, it was at $3.55 compared to $3.05 for gasoline.