Where's Dion when you need him.
Sorry guys, other side of the world.
It depends how greasy you want to get and how much you want to pinch pennies.
You want an FS5W71C with Z/KA bellhousing, fitted to:
D21 4x4 86-96 Z24/KA24E
D21 4x2 86-92 Z24/KA24E
WD21 4x4 86-96 Z24
D22 4x2 97-04 KA24DE
Mildly useful:
E23 4x2 ?? column shift Z24
E24 4x2 ?? column shift Z24
(^Urvans)
Obviously a 4x4 box is less of a risk than a 4x2 box but you can always swap the gearset across and hope the tolerances are similar between the two casings, IF you can't easily swap the casing to accept the transfer case.
You don't really want an FS5W71C with TD bellhousing, fitted to:
D21 4x4 88-96 TD27
D21 4x2 88-96 TD23
WD21 4x4 86-88 TD27
WD21 4x4 88-96 TD27T
But the gearset will interchange.
You could also scrape by with the gearset from a FS5W71C with an SD bellhousing, fitted to:
720 10,000BC-86 SD23/25
D21 4x4 86-88 SD23/25
D21 4x2 86-88 SD23/25
You definitely don't want an FS5R30A with any bellhousing, totally incompatible, as fitted to:
D21 4x2 VG30
D22 4x4 QD32
D22 4x4 ZD30
D22 4x4 VG33
I would steer clear of buying one that hasn't been rebuilt from a wrecker unless you get a sizzling deal, as you'll be back at square one pretty quickly, 200,000 to 300,000 is when these usually spit fifth gear. You can have rebuilt exchange boxes from eBay for about $1500 from time to time, I think that would give you the best bang for buck. And run synthetic gear oil in your new box.