I have the heavy duty non-ceramic and it works fine. I have a very sloppy clutch habit/skill, and it's still working fine, despite abuse that would have roasted a stock OEM clutch in under a year. Best was hammering it up a steep hill in the rain that I was forced to stop on with 4 people in the truck. Actually slid backwards about a yard due to my tires sliding it was so steep.(ie - tires spinning before grabbing). Clutch was unfazed. Couldn't care what I was doing to it, near as I could tell.
(guy behind me, though, was probably needing new shorts by the look on his face)
Stock on a 4 cylinder is/was 900lbs, IIRC. That's way way too low - basically the same as a stock 2wd pickup/donor of the same year. (oversight, IMO, on Toyota's part)
Note - this is a 1600lb clutch kit on an 87 4Runner at about 4200lbs with the extras I have on it. Lovely, really. So far I've heard nobody ever complain about it here.(opposite, really - loads of love for it)
The ceramic will probably be my next one, though, since I personally like a ceramic's feel. But it really IS on/off - there is an actual slight jerk most of the time when it's put in gear from idle. 95% of people don't seem to like this - go figure - heh.
Oh, ceramics are great off-road, but they also are stupidly easy to stall with stock gearing in first gear in heavy traffic. There IS no creep or feathering of the clutch in and out. It's 5mph or neutral, nothing in between.
