[Lucky]

For street or track use?

If 90%+ street... don't do it.

If mostly a track toy with occasional street, then go for it. Make sure you use a spring centered clutch disk (to absorb driveline shock that was previously absorbed by the DMF) and seriously consider putting the 3.8RS's harmonic dampener on (it replaces the accessory drive pulley at the front of your engine and will reduce the chance your crankshaft will fail).

Enjoy!

BTW I had a lightweight flywheel and clutch kit in my old 911... it rev'd like a superbike, idled like ******************** (hunted all over the place), and was a b*tch to drive smoothly on the street. But it was awesome on the track.