You can get this answered quickly and accurately at
http://forum.miata.net/vb/index.php?
It's a site like Pelican, but specializing in miata. Most of the people are great and there are plenty of knowledgeable people.
My .02. I'm pretty good with miata, but I haven't had to mess with my clutch yet, so I can't answer your question. If it's slipping then you need a new one, but you already knew that.
__________________
Steve
'08 Boxster RS60 Spyder #0099/1960
- never named a car before, but this is Charlotte.
'88 targa

SOLD 2004 - gone but not forgotten