SPEC Stage III Clutch users here

SPEC Stage III Clutch users here
I have a stage III kevlar clutch from SPEC on my Stroked LT1
I'm making about 390RWHP but plan to go above 400.

The current 4 disc Kevlar only lasted about 12k miles.
the thing will lose holding pressure after getting hot now.
I have hardly ever driven the car hard and have never droped the clutch at high RPM. I do mostly street driving in moderate traffic at times which means some stop and go casuing me to slip the clutch a bit to get started. this is needed with the bigger cam I have and the chatter I get with the Kevlar material.

Is this normal wear people are seeing with around 400RWHP?
Spec says it is supose to hold much more than this BTW

And,
I hear that SPEC now has a 6 disc carbon version that is not as chattery as the kevlar and holds just as much as the Kevlar.
Anyone have some feedback using the newer 5 disc with more than 400RWHP? Chatter in daily driving? Hold at the track?

What would people recommend for a replacement?

What does Spec have to say about this?

Anyone else experience similar failures? I am considering a Spec St.III for my build, which will make about 500rwhp. I'm concerned that this will not be up to the task.

Mike...

i just emailed SPEC about this. I will be waiting for their reply.
I have a feeling that the stage III design was updated since i purchased it. The Stage II seems to have Kevlar now and the Stage III now has Carbon and ceramic options.

So maybe the original claims of the Stage II HP rating was off?
I hope someone posts with some info as I know for sure that some people know why the design has changed.

Yes, it's normal for a spec clutch to burn up after a short time. The're crap. Thats why mcleod rules.