Originally Posted by
noglider
Thank you, everyone! I will measure the splines. I think I'll see how this lock ring holds up and won't seek a new one. I'll just make sure it's good and tight.
If the lockring is steel & serrated, and engages a couple of tread, it should be fine. Most of the force in the sprockets are rotational and supported by the splines.
About removing the freehub body, only necessary if maintenance is needed. Very hard to find a replacement that will work on the 74?? series, and only 1 style 'natively' takes a HG cassette (the one that you seem to already have).