Was going through some of my buckets of random SR parts and I found these. I'm not an expert, and simply know how a diff works. What I do not know is what kind of diffs these are.

Diff one had a ring gear on it. Not sure which one either, it did have some numbers on it though.




Here is the second one.




I think they are just 180sx vlsd's but I'm not sure. Thanks in advance for anyone able to identify, or show me where/what to look for in identifying these.

 

The stamping "49:12" is the number of teeth of the ring and corresponding pinion. That's 4.083, or stock S13/S14. Those look like VLSD units to me.