got the plates (kx80/85), fit them, rode it. pleased. that's the short version.
long version- 1) is a little tricky getting the tabs filed equally so plates fit. the overall dia is just under the advertised size of 110mm but not by much so tabs have to be just right.
2) the stack of plates comes out to about .008" less than the stock so I was not concerned about using them with the pin-type center hub. the threaded type would be easier but I couldn't justify the cost to buy one.
3) I used only three springs. I believe they are heavy duty ones. possibly Barnett- dad couldn't remember, it's been years since he changed them. and apparently he lost one as there was one that was a little shorter and plain gray, not black, like the other 5. assuming that one is stock.
4) the pressure plate does move out slightly unevenly, which could be addressed easily with a threaded hub. I think the problem is the spring cups, being stamped, are not equal depth. out of the six I'm sure three the same size could be found.
5) no slippage, kicking it over or shifting into high gears. hot or cold it kicks over fine and I rode it down the street, shifting up, lots of throttle, and no slipping.
6) engagement is nice and smooth, not grabby at all
7) clutch pull is much easier than before, not modern bike easy, but still a big improvement.
8) paid under $20 USD for the plates!