changing shimano cassette body
I've got my hands on a couple of nice older Shimano cassette hubs. One is a dura-ace, the other is xt. Both are the old 6 speed type, where the smallest cog threads on as the cassette lockring. I'd like to update these hubs so they would at least take 7 or 8 speed, and use the newer lockring style.
My question: if I put my hands on some updated cassette bodies, will I be able to install them on these older hubs. I'm aware that I may also have to install a longer axle (maybe not), so my question pertains more to whether the internals are compatible--will I be able to use the same internal bolt that holds the cassette body to the hub, and will the body mate up to the hub without any non-compatibility issues.
Anybody ever perform this surgery?