I recently purchased an 01s4 with 40k and a blown engine. I also bought a replacement engine with 80k. So i took the clutch off both engines thinking that the 40k one would be in better condition. wrong!!! Anyways i noticed that the disc from the 80k engine was slotted and the other one was not. The 40k disc didn't look like it was previously and that the slots were worn through. There's a couple different numbers between the two. Just wondering the difference is between the discs. Aftermarket replacement, different year, ect...

 

ummm..
well it looks like the clutch on the left is still in good condition... and the one on the right is just about completely worn out...

 

sounds like it was a 40k car that got all it's miles a 1/4 mile at a time...!

HAHA