Help ID Tracloc

I bought a clutch style lsd from a member on a different sight who said it was for a 8.75 back in March of this year. Went to install the ring gear and though it seems like it wants to fit, the ring gear bolts wont seat completely due to the shoulder above the threads. Something to me seems wrong. I've even ordered new bolts & same deal. I ran all the numbers I could find on the carrier with no luck & put it out to all you guys to see if you can help. I have a feeling I'm looking at a dana 30 or dana 35 misidentified as a 8.75. Would be nice to find out otherwise. Help please.

Numbers on carrier:
21745X
C30847
670B