OK so back to the clutch issue...
I bought my 4runner 25,000 km ago and the clutch has never been very peppy. It feels a bit sloppy and it engages near the top of the pedal stroke. I am wondering if I should just bite the bullet and replace it pre-emptively now. I was planning on it. I bought the Marlin Crawler one. I don't clearly recall it slipping but with it engaging so close to the top, it must be getting near the end. If this was my daily driver then I could just drive it till it was obviously slipping but I use this truck for long trips into the middle of nowhere so I can't have it causing problems mid way into the trip. It has 291,000 km which is 180,000 miles. Based on comments above it is probably still the original clutch and others have had theirs last longer than this. I replaced master and slave cylinders recently and saw no real difference in its performance but they definitely needed to be changed.
Also while in there I'll do the rear main seal.