Looks like the rear stock '98 driveshaft will fit if I swap in a yoke from a NBS driveshaft. By my measurements, the new trans and tcase combo is within a 1/4" of the old setup. The front driveshaft is coming from a NBS because of different length and attachment at the t-case.

As long as the motor ends up in the same spot as the old one, everything should fit how I plan. Should find out in the next day or two.