We have been driving around the new single-disk-clutch aluminum flywheel for 1987-1995 928's for a month or more now with no problems.
Its very nice, works great, even with the hi-clamping force GT2 clutch I have on this supercharged 928.
Two types of 928 owners might be interested in this item: those that need to replace their flywheel due to wear and cannot find an affordable replacement; and those that want the faster throttle response in both accel and decel that a lightweight flywheel provides. This flywheel is 3.6 lbs lighter than stock, so the difference is significant!
Flywheel is fitted with a replaceable steel insert, so should it ever become necessary you can simply bolt in a new friction plate and keep going.
The 60-tooth timing ring is heat-shrunk and pinned in place by us before shipping, so the flywheel is ready-to-install upon arrival.