The Stieber sprag fits, its exactly the same size. In fact it appears to be identical in every way, so I dont know if it's any stronger than OEM. My sprag must have been slipping for a lot longer than I noticed because I'm surprised how fast my C5 stars now. I'll have to see how long it lasts.
I like that the new clutch has that spring band going down the middle of the sprags. That tends to keep them tucked out of harm's way unless there's enough centrifugal force to engage them. It also has they wavy wire cage to keep them located, more flexible than the solid sheet steel style cage that can shatter when the engine kicks back.Scott