After reading all the reply's, I have to jump in on this. First off im gonna tell you I am VERY familiar with the 7.3 power stroke. VERY. The 97 7.3 you have is direct injected and uses a high pressure oil system to fire the injectors. The reason I am so familiar is I have repaired what seems like every one in the north east. Not to say it is not a good engine but it has its issues. Injectors are not cheap but not crazy expensive. also there are 8 not 6 like the cummins. the non electronic cummins is very reliable except for the pump which is not cheap. the 7.3 has many places for oil leaks. it has a high pressure oil system to run the injectors as well as a harness that is problematic with age and a glow plug system that it needs to start . To swap in the 7.3 you will need to use all the electronics from the ford and adapt that stuff to your old dodge truck. that means both the ford PCM and the IDM that runs the engine. The 7.3 will make plenty of power but is very thirsty. I cant believe that the cummins wont fit in that engine compartment it fits in my 89? then the year after that dodge figured out how to fit an intercooler in too. How deep is the engine bay in that year truck? I think the cummins would be a better swap but the 7.3 is not undoable. Just a lot more work and potently more expensive in repairs down the road. You have a lot of thinking to do and personally I think its a waste of time and money. Just go buy a newer truck with a diesel in it that will do all the things you want. Good luck