Kyosho cup + internal gear + cross pin + ring gear is a direct replacement for HB diff.
I know because when i've my LSP, i explode the rear diff on the breakin-in, and a friend of me tell me that's the only thing to do to bullet proof the weak HB diff is to put the Kyosho diff cup and internal gear.
That's what i've done and no more problems.

And i've just recieve my RCM V1 hybrid diff for my revo and when this HB diff will died, i'll build it with Kyosho stuff.