You might want to learn a little bit about what you think you want to get involved in before you set out to build something to run a series that you cannot run. SCORE doesn't allow superchargers or turbos. CORR doesn't have a class that the X would be able to fit and it would be a really bad idea to race an X on a short course anyways considering the short wheelbase, tall ride height and limited gearing options.

Also re: RDC:
A) they have a tech forum. In your case it would have been performance/engine.

B) you cannot use turbos and superchargers in mose desert racing aplications so no, not many guys deal with the. And there are very very few guys running Nissan anything anyways.

It would be a gigantic time of money, time and a perfectly good Xterra to not know anything about the sport and jump head first into without sitting on the sidelines for a little while and getting yourself an education.