Not anywhere near the highest of those posting here but my '87 4.0 has 210K on the clock and doesn't take oil between changes. Probably 99% of the stuff under the hood is the same stuff AMC put in when they built it, did change a TPS with one from a junkyard a year or so ago and changed out the original AMC plug wires a couple months ago. Bought it well used so it's probably had a TPS changed before.
Runs smooth and quiet and I don't know what the compression is, or that it really matters since it's not like you could adjust it or anything - there's just nothing going on that calls to taking the time to :repair: check it.
The muffler and CAT are starting to open up, I can tell by the tone

assgas: and the fact that RPM for peak torque is creeping up (put another way, it is losing some low end).
D44 :yelclap: in the rear is looking good, the front axle oozes here and there.
And the Peugeot tranny

uke: ? It's quiet but the synchros are shot and it leaks oil like a sieve. I'll probably be needing to slide in an AX-15 or wedge in a New Venture sometime soon because I want to tow a camping trailer. We're getting too old & worn out to do the tent thing and it's already rigged up with a nice Draw-Tite full sized receiver.
Clutch and that stupid internal slave were brand new when I bought it, as was the radiator - original surge tank style but there's nothing wrong with surge tanks per se and mine isn't broken.
Body tight, no leaks, no dents, no rust. Clear coat is coming off the hood & roof and I haven't decided whether to try and fix that or do a full repaint in low gloss black or CAMO :dunno:
But I digress. The theme here seems to be the 4.0 has impressive (at least among us :worship: ) longevity and it's a wonderful powerplant behind which we can place any number of cheap and easy upgrades and enjoy countless miles of fun

arty: .