I'll add the MK III Differential Options by Year & Model
(Copied from Mkiiitech.com - posted by drjonez 24 Aug 03)
'86.5 - '90 GA70s w/the 1G-GE have a 4.56, clutch-pack or Torsen LSD 7.5" differential, NOT compatible with any of the other A70 diff setups.
All 1G-GTE equipped GA70s have a 4.56, clutch-pack or Torsen LSD differential.
'86.5-'92 MA70 N/A MKIIIs without Sport Package have a 4.30, open differential.
'86.5-'92 MA70 N/A MKIIIs with Sport Package (TEMS & headlight washers on '86.5 - '88 : TEMS & PPS on '89-'92) have a 4.30, clutch-pack LSD differential.
'87 - '88 MA70 turbo MKIIIs have a 3.91 clutch-pack LSD differential.
'89+ MA70 turbo MKIIIs have a 3.73 clutch-pack LSD differential.
'90 - '92 JZA70 Limited and R MKIIIs manual trans cars have a 4.10 Torsen LSD differential and auto trans cars have a 3.91 Torsen LSD differential.
Note that a LSD was an option- so you could get a NA base model w/a LSD.