If you have not figured out what diff you have, Pm me with a picture and I may be able to identify.
I have just finished swapping a 350Z/G35 diff into my S14. I bought a pathfinder diff and returned it when I found out it was not a limited slip as I was told at the wrecking yard. There were no other pathfinder diffs available locally so I opted for the 350Z/G35 unit. Having both at the house, I can say with certainly the 350Z, G35 and 2005 & later Pathfinder cases are identical in size and shape. They DO NOT bolt into the S14 sub-frame. I have included a link to a site that explains how to modify the S14 sub-frame to bolt any of these three diffs into your car. He took very good pictures of the modifications also.
Wrecked Magazine – Dennis » Blog Archive » 350z Differential Install into a 240sx
Be sure to read the comments below the pictures where I detail what options you have for axle and hub combinations.