blown engine 2.5tdi

Hi all. I have a problem - my 02 2.5Tdi engine is goosed. I have a 96 (old model) passat 1.9Tdi with a good engine but the car is pretty much scrap. It would make lots of sense to me if I could put thePassat engine into the T4 but suspect it would be a nightmare. Has anybody heard of this...