Need some info

[strecks]

ok so I am new here, I have a 2000 f350 with a 7.3 turbo. I use it to haul fiberglass swimming pools....lots and lots of wind drag. I am looking at a 2000 international with a 7.3 turbo to add to my fleet...ya right fleet. Anyway, I am told the turbo is not working and that there was oil and diesel fuel under the turbo. I guess I have 3 questions....what parts are interchangeable between the ford and international versions, can you do a complete engine swap between them, and lastly I was told that the oil and diesel leakage was a sign of an upper engine problem. This truck only has 120k miles on it and was an old fire rescue vehicle so it was well maintained, so my last question is ..is this a potentially a big problem?

thanks in advance