I'm told the newer style clutch is the better clutch and I can certainly vouch for the improvement in throttle response, as well as shifting, with the lighter /7 flywheel I just installed. I imagine the change would be even more dramatic with the even lighter later clutch assembly yet.
and here is the quote from Snowbums web page:http://www.bmwmotorcycletech.info/transmission.htm
8. In 1981 BMW made changes in the transmission clutch throwout bearing area, internally as well as the external shift lever arrangement. Also in 1981, BMW made a large change to the clutch and flywheel, which became a totally different design, and the flywheel is now called a Clutch Carrier....and the transmission input shaft was changed (shorter) to accommodate those changes. Transmissions before and after that date can be interchanged if the input shaft is the correct one. The input shaft is about 24 mm long on the early transmissions, and from 1981, it is about 19 mm long. It is also possible to shorten the input shaft on an early transmission, in order to fit it to a later clutch unit...by simply using a cutoff disc, etc., even with the transmission still together!
Be sure to radius the forward edge properly. Within certain guidelines, such as the input shaft length, and internal gears angle cuts, shift kit or not, proper neutral switch...etc...as all mentioned in this page, most all the transmissions generally interchange.