well, I didnt see anywhere that said they were different for SC or NA when I was looking for a muffler for mine.
But if you wanted to check for yourself, look at the last diagram on this page, providing yours is a 4WD,(you failed to mention what you have, other than the year) 2WD diagram is also on this page though, looks to me like they are showing them to be the same if its SC or not.
http://www.courtesyparts.com/xterra-part...14_467_468.html