FWIW, my uncle ran one of these to 950K, with the head rework at 600K.
Sounds like what I want, except I would prefer a 350 for the solid front end. The 6.9 WILL be oily underneath, just the nature of the beast IMO. I had two of these motors and both leaked oil, one was purchased new by grandfather and had under 100K. I think outside of a normal vehicle inspection, there isn't much that I can remember since it been 10yrs since I had one of these. I would be focused on owner history, and how they treated it. The front end has a tendency to shear the ears off of the outer axles (mine did it once). I have been told this occurs when you get wear in the outer u-joints and it goes unnoticed. Expect your top speed to be 72mph it it has 4.10's, unless the injector pump has been turned up. How many miles, BTW. Good luck and post pics!!!