Hi all,
The old style Honda Valkyrie suffered severe failures if the rear splines weren't religiously maintained, - and sometimes even if they were (DAMHIK). Some guys on the VRCC forum persuaded a company in Houston, TX to produce a moly product that would fully protect the Valk's rear splines, and apparently it works extremely well.
https://guarddogmoly.com/product/gd-570-moly-paste-antiseize/
Personally I didn't use it. The local Honda shop (whom I trust) came to recommend Bel-Ray assembly grease. I sold my '99 Valk for my Rocket III (standard) in 2010 and have 41K miles on here using the Bel-Ray. I check the splines every rear tire change (MC tire) and they are perfect.
Hope this helps,
Mark Dunn