Maybe this will help you make a determination:
FACTS:
LSD was NOT available on '91-92 cars.
LSD was an OPTION beginning in '93.
LSD was ONLY available on the 3sgte (E153 tranny).
It is a visous coupling and CANNOT be identified by jacking the car up and turning one wheel.
Cars equiped with factory instlled LSD will have a data plate in the drivers door with an "A/TM" designation of either E153/733, or E153/735.(as stated by Ghostyman)
All MkII MR2, turbo or N/A, open diff or LSD will spin both rear wheels.
If you look into the axle port of a factory LSD tranny, there will be visible bar between the 2 side.