difference in pumkin ??

[s13driver]

i was so curious about the size of the pumkin between an open differential, vlsd, off either S13, S14, 300Z, J30  and is the difference between them ? is the size of inside the pumkin the same goes for all of them or they are difference because some of them have abs sensors ? lets say if i swap out the open differential off the S13 and replace the differentail off a J30( all year ) or 300Z ( all year )will that work... is the differential a direct bolt on without any extra parts needed ? i m not talk about the whole pumkin but just the inside of it... thanks