My friend's reply:
"As for the clutch stuff, I believe those contours don't have a pilot bearing. We see issues with ours and
other brands of clutches when used on non-piloted setups like that all the time... The lack of a pilot bearing/bushing allows the input shaft to walk under torque and acceleration/deceleration. In fact, it goes back and forth when you accel and decel. The more miles on the car, the worse they get; it's due to a worn input bearing. The eveidence of this "shaft walk" is seen where those springs in the disk have "wobbled" their way around in their retainer plates (see pic below)... and you can see they have worn their way out. I've seen some of the disks with the "captured" springs, but it still allows the springs to wear out within the retainer plate and the loose springs still get lodged and jammed in sideways and break. Believe it or not, I've actually seen these occurrences on mitsubishi eclipses more than anything because they are 4wd and turbocharged, sometimes pushing upwards of 500+hp... with NO PILOT BEARING! That pilotless design was never intended to see that kind of loading. We see all kinds of problems with those at high power becasue people are not on top of their transmission. The best fix is to make sure the transmissions are gone through and that the input shaft and bearings are at the tightest possible tolerance regarding their "end-play" allowance. Those are the ones that get the longest life out of a clutch with no pilot bearing. Another way to remedy it is to just get a disk with no springs. Instead of ordering the Stage 3+, it would be called the Stage 4+ which is a solid-hub version with the full-faced "carbon semi-metallic" lining. It's a little more aggressive on the engagement, but without the springs, the disk sort of acts as a pilot for the shaft and is much more rigid. And no springs to wear through the carrier from shaft-walk. But I still recommend having the endplay checked on all transmissions when they're out of the car.
We have springs exactly like these in V8 cars making 700ftlbs torque. That's why we use the same springs, hub, and carrier from stage 1 up to stage 3+. The other disk I saw in the thread looked like it had a rivet pull up and cause some problems, that is an entirely different situation and SPEC usually addresses it differently with a repair or replacement, as long as it's not too far out of warranty. SPEC has 120 day warranty. For comparisson, I've seen a 90 day warranty on another big brand clutch company. SPEC is very realistic with their replacement and warranty policy... it simply cannot be "free lifetime replacement" which some people seem to want. SPEC does a good job with helping customers out and often times offers discounts to repeat customers and anyone who has had problems with their setups."
Hope this helps.
-J