Shot in the dark here, body could be a Collins.
There's a lot to consider for newbies, a lot of which most don't think of. I have a buyer's guide I've compiled and some other info I send new folks to help them along and avoid problems.
The 6.5 isn't a terrible engine, but it does have its issues - It is based on the preceding 6.2L, which is known for head and gasket failures, as well as main bearing web stress cracks at higher mileage. Not all of them do it, but it is somewhat common. Also, if you're not familiar with diesels, three things you should know. They are picky about fuel pressure, fuel quality, and DO NOT like water in the fuel. Check your PMs, I'm sending some info your way.