High mileage 5.3/6.0

[Tilt]

I've been looking for either a 5.3 or 6.0 to swap into my 86 step side. I would rather by a complete donor than just a motor/trans. A lot of the vehicles I've been finding have 160,000-200,000+ miles on them. Should I stay away from something with that many miles, even if runs good/sounds good? If I did go with something with that many miles, would it be necessary to pull it apart and freshen it up? What would ya'll recommend doing to it before the swap? What parts to replace? The 86 is not and will not be a DD, just something to have fun in on the weekends if that matters at all.