4wd Checklist:
4wd Transmission. In your case, a 4wd BA 10/5 or 4wd AX-15, preferably AX-15 but you'll need an AX-15 crossmember if you don't already have one.
Transfercase.
T-case handle, linkages, brackets.
Front axle.
Rear axle to match front.
Front Driveshaft.
Shorter rear Driveshaft.
You may need a longer speedo cable.
You don't need to worry about the vacuum harness, just lock the CAD and forget it.
That's about it unless you're converting to an external slave at the same time.