You might have posted a link Gary but what is required for machining later model clutch baskets?
Here's Ippys how to read this, and his next couple posts.
http://www.xs650.com/threads/alto-8-pack-clutch-kits.33399/#post-342646
I've got to look through this myself, I have a late clutch apart on the bench.
Quote from ippy's post
"Okay here is a brief run down of what is needed to convert the later (late '78-'83) spring loaded clutches to an Alto 8-pack clutch. If you have access to a lathe or a good machine shop it is quick and inexpensive. Sorry I did not get any pictures of the inner clutch boss prior to machining, maybe someone can post up a pic, but I do have a simple drawing of the profile so that there is at least some representation of what was done. This guide is written assuming everyone knows how to access the clutch and remove the inner clutch boss.
1. Remove - ring, clutch boss (item #8); plate, clutch 2 (item #9); spring, clutch boss (item #7) and plate, seat (item #6)
2. Machine or have the inner clutch boss from original to like the modified clutch boss in the attached diagrams.
3. Re-install modified inner clutch boss.
4. You can probably re-use the plate, clutch 2 but mine had a groove on the bottom side and I used another of the regular steel plates.
5. Install Alto clutch plates and steel plates starting with a Alto plate and alternating with the steel plates.
6. Re-install pressure plate, springs and screws. Button up the RH side cover, fill with oil and have fun.
There is no need for any machining of the outer basket or the back side of the inner clutch hub. All machining that needs to be done is as shown in the diagrams and the finished picture."