Not going to happen - at least, not directly with the '88 components. The one major issue that I can see here is that your '88 transfer case has a 21-spline input, but your '98 transmission has a 23-spline output. Basically, unless one or the other is changed to match, they won't mate up.
If the transfer case in your '88 is an NP242, you're in luck - the front axle doesn't have a vacuum disconnect, so that at least can be moved over wholesale and a later transfer case (NP242 or NP231; doesn't matter) can be used. However, if it's an NP231, it'll have the vacuum disconnect on the axle; you'll need to disable this before using a later transfer case.
Those are the two big considerations in all of this, but there are a lot of details I've left out. If you're really set on getting a 4WD donor to swap components from into your '98, look for a '91 to '99 model; check spline counts on '91s as some were 21-spline and some were 23-spline.