My wife's 2000 (My old truck, and still hunting rig) has 163,xxx on it and runs great. It did pop a plug about 30,000 miles ago, but I think it was my bad, as I had recently given it a tune up and used Bosch plugs... (I have since learned to use only the Motorcraft or Autolite platinums). It has a small oil leak near the intake manifold somewhere, so I have to keep an eye on the oil, usually adding a quart between changes at 4,000 miles.
I never replaced all the cops at once, instead replacing one at a time, as they go bad. I have replaced 6 as of now.
I put an Auburn limited slip in the rear ab out 7 years ago, and while I had it all apart, I went ahead and installed a new ring and pinion. It didn't need to be replaced, but I figured I might as well do it so it would last that much longer.