I've done this a few times now on the Frotiers, but it will work just the same on an Xterra. These are the new OEM replacement Bilsteins for the Titans. The lower unit is the titan, upper is a stock offroad/nismo shock. Note that the circlip groove is higher on the new shock and that the lower bushing is bigger than stock. These will bolt directly in place of the stock offroad shock (with disassembly of the stock set-up) and provide about 3/4" of lift. The valving is a bit stiffer too and will provide more bottoming reisistance and better vehicle control (still nothing like the Radflos, but better than stock and a good price point). The body itself is a bit longer but does not hinder wheel travel. These will also bolt on to a non-offroad x as well, but you need the lower spring retainer fro the offroad model as these come with the one for a titan and are too large for the smaller xterra spring. See pic two.