Miata peoples - Tranny and Diff fluid reccomendations

[PDenbigh]

What do you guys recommend for the manual tranny and diff fluid in a Miata? It's Alisons 1995.

I'd like something that can be purchased locally if possible. I'm not sure if it has a limited slip, so please provide suggestions for both.

Also, I put Royal Purple in it last week, and it has stopped ticking. I tried every brand synthetic and RP did the trick. Interesting?

Thanks!
Peter