I have only had one 4.0L with more miles than yours and it was a 1991 Exploder that had about 270,000 when I sold it, and it still ran great, I sold it about 3 years ago and I saw it drive through town a couple of weeks ago, so the truck is still going anyways, I have no clue if it is still the same motor, the ranger with a 4.0L I am driving now has about 157,000