the compression ratio of the N/A vs. S/C xterra is the same... And we already know that the block is the same. With this information, it is reasonable to assume that the engines are identical from N/A to S/C.

Anyone know of differences with the ECUs? I've got a Tacoma S/C'd and it's not as easy as "bolt-on" as some of you make it seem. Having gone through it, I can elaborate: Yes, the S/C is basically a bolt-on... And you will get boost. However, you will also get horrible detonation. In order to have the system work worth a damn you must get either the 7th injector kit, or something like the URD kit (I went with the URD kit). After installing that (new injectors, fuel pump, wideband O2, and controller) and spending some time with a passenger and a laptop for tuning you're in business.

Overall cost was $2200 for the S/C and neccessary parts for that, and $900 for the fuel upgrades.

I see no reason that something could not be done similarly with the Xterra. However, one must ask why you bought a N/A xterra only to want a s/c 2 days later?