Not so unrelated to Xterra stuff, BUT this looks like a way to possible beefen the Nissan IFS system? I know it would be lots of work, but would be damn near bullet proof! I had an '89 930 and upgrade the motor to over 600hp and never did anything to the Driveaxles or CV's. Very tough parts.
http://www.rockstomper.com/catalog/drivetrn/930.htm