lsd question
 

i have an na 95 1.8 na miata with an open diff. i believe i can throw a torsen from other na miatas in without switching anything but the diff itslef. correct me if i am wrong. but i was wondering if i can swap a torsen from an nb model over the same way or if i need everything with it? ps i want a torsen if anybody has one. thanks

you can also use some N/A Rx-7 guts if I'm not mistaken.

but can i use the nb torsen in my open diff iwthout any other nb parts?

yes

Yes. Keep in mind this will change your gearing to 4.30 though which may not be what you want. Find out if you have 3.90 or 4.10 right now and decide wether you want that gearing bump. At 65 mph it puts me at almost 4k rpms.
-Ryan