These all have Suzuki 1.6/auto/6.5 sammy cases, with mini truck steer diffs front and rear. Chromo cvs and axles, drive flanges etc.
The white one has 37 treps, the green and red 40s, the red one broke the drive flange bolts on the front (australian) drivers, but I don't think they were upgraded ones.
The white one bound the rear drivers up crazy and drove out of it, I was cringing waiting for something to pop.
Green one held up fine, Previously only issues have been a broken ring (not a nitro i don't think).
They do hold up fairly well with minimal issues, but our rocks generally have a lot of grip so we don't have to throw stuff up climbs and can keep it fairly controlled.
There was another sammy based rig down here with a 3800 GM v6 that had alot of luck with his mini truck steer diffs but has since upgraded to fj80/9.5 hybrid axles.
Some have broken them, but they do have good success with good driving.