Wide or narrow 231 Transfer Case Chain?

Hi:

- '91 XJ
- 4.0L HO
- AX15 tranny
- NP231J T-case

I searched but couldn't find this.

Do I have the wide or narrow drive chain in the T-case? I'm going to do a rebuild, and I'd like to order all the parts before tearing it open. Is there a way to know beforehand what chain I have? The T-case has never been modified.

Thanks!

231J case should have the narrow chain. 231D cases (maybe others) have the wide chain.

IIRC you can upgrade to the wide chain by replacing the sprockets. I don't think anything else is necessary.