86 f250 6.9 4x4

I'm planning on going to see one of these diesel pickups and am looking for any points of concern that I should look for/at. My intentions are to haul lumber, the occasional car and to pull out my friend when she gets stuck in the snow.

What are the typical miles before a rebuild or replacement? How reliable are these engines? Warm up time on a cold (10-25°F) day? Tongue weight, if anyone knows off-hand. Etc.

Please feel free to put any useful information out here.
TIA Ted