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zerothread?id=385327
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Z32 NA Diff94 or older J30 axlesSwap your stock cover onto the Z diff (only for S13)
That will work with your stock 4-lug hubs and your diff input flange will be in the same spot as your stock diff so your driveshaft will work fine.
The longer bolts people refer to are the two bolts that hold the pinion end of the diff to the subframe. Since the Z32 diff has rubber isolators at that point longer bots are needed to accommodate for them. By the way, this is only true for an S13.
The reason some people say the Z32 diff is "waayyyyyyy harder" is because you need J30 axles to make it work. That, or you need the differential output shaft/flanges from an S13/S14 that has a stock LSD and put them into your Z diff so you can keep your stock axles. There is no known strength difference between the J30 axles and the S chassis axles.