There is no difference between a 200SX R180 and a Z R180.
Remember, a 200SX has basically the same rear suspension as a 280ZX. So long as you have a car that has snap-in axles, as opposed to the single bolt style, it should be a direct swap.
You can find R series diffs on several japanese cars. Toyota trucks 4x4 use them for front drive, early Maxima's with the L-series engine, 200SX, 280ZX and some Subaru's. Basically, the company that makes the diffs, subcontracts to all the japanese auto-makers. Similar to how Sumitomo supplies the brakes, which is why the Toyota 4x4 swap works so well.
Dave, thanks for the post. I thought they all looked exactly the same. Even if the half shafts are different lengths, I could use Z half shafts.
QUESTION: Which R180's had 4.11 gears? I can't find any 200SX Turbos (they are rare) to get a R200 with a 4.11, so why not find a R180 with a 4.11 if they exist. That way, I can use the ZX 5sp I have. If I can't find a 4.11 rear end, I will have to find a '75-'78 Z 5sp to couple with a 3.90 R200. Since I already have a ZX tranny in the garage, I would rather swap in a R180 with 4.11. I checked the final drive number, and this gives me what I want. What are your thoughts?
You're on the right track the 4.11 with ZX 5spd or 3.9 with Z 5spd offer the best acceleration. The gear sheet should indicate which cars came with R180 4.11 diffs. The R180 should be much more plentiful than the one year only R200 4.11 in the turbo V6 200SX. Just be aware, that if you have alot of engine mods, the R180 will begin to fail. Trust me, my original R180 is hating life right now.
No need to send me the gear sheet, I already have my original.