what diff housing(/axles) do I have (and what LSD will fit?)
 

The chassis is an '89 from Japan, with a '98 S13 SR swap (and selected interior pieces - including the oh-shit handle!)

Can anyone tell me what diff housing I have? I was told the LSD (either 1 way or 1.5 way) is a Nismo, but I've never actually popped the baby out to check.
Basically, i'm clunking like a mofo and the clutchpacks are not locking (even in the rain on 10-year-old 195/55/15 Yokohama AVS ES100s -- until I really push her out) and so I'm thinking of upgrading to a new LSD. The Tomei TTrax comes to mind, but also open to suggestions. (Wonder if Nismo still make the SSS? Ha!)

When buying, say, a T-Trax, will the one designed for a USDM open diff fit, or do I need the one for the the US VLSD housing? Or will neither of these fit and I will need one for a Japanese model... if that's the case, can you tell if I have an '89 Japanese Open/VLSD, or a '98 Open/VLSD housing? Any idea about the part number?

Ideas where to buy? (will be shipping to Hong Kong...)

Many thanks to all - any help would be appreciated. Pics attached.

Nobody? ... just looking to figure out which model of LSD to buy that will fit this housing and output shafts... Thanks. :)

Looks like a long nose VLSD from a 300zx. Dont quote me been out of the 240 game since i finished my build. I have a NA Z32 VLSD with J30 axles. There is a page out there with all the info youll ever need 240SX LSD Swap

You have an R180 diff and housing. Pretty much after 89/90, Nissan changed the rear end to the run of the mill R200 diff. Some NA JDM S-chassis still had them but not a whole lot. You can't just swap out the diff for an R200 diff since it wont bolt up to the subframe. You pretty much have to swap the subframe, diff and axles from you to utilize an R200 rearend.

Thanks, fliprayzin240sx.
What gives it away?

And am I correct to assume that an LSD designed for an RPS13 (with matching R200 diff) will NOT fit in my R180 housing?
Man... I have no idea where I'm going to get a R200 here in Hong Kong...

Correct. Any R180 will not accept an R200 differential and pinion/ring gear. You really shouldn't have too much of a problem finding one over there.

That is a standard R200 with 6 bolt axle shafts. Pull it out and open the cover to see what kind of lsd it is.

Incorrect. It's not a long-nose diff. It's a short nose. Google will show you the differences.

Two incorrect things here. 1, it's not an r180. 2, even if it was, he wouldn't need to swap subframes. S13 subframes have holes for both the r180 and the r200. You only need to swap subframes to use an r180 in an s14, since the s14 subframe has the 2 bolt rear diff mount.

This is an r180. See the use of the inner bolt holes?
Nissan Road Racing Forums - View Single Post - R180 Differential

This guy knows what's up.