The path of least resistance is to get a new TRD LSD, it seems like a lot, but compared to figgiing around miss matching GTZ parts with std 101 parts, fitting the LSD is the easier option.
If you were to put it in a box you already have, (and not re-con anything) you should get away with it just under $2k.
My experience was around 2500 - 3000 as there are always little bits you 'might as well do now' while your at it.. mounts, flywheel, clutch, bearing, syncros etc...
and its well worth it
