This is retarded. N/A is the antithesis of Forced Induction, thats it. It does not imply mods, or bolt-ons, or a fully built motor. It means that air is not being forced into the motor with an external pump (turbo or supercharger). I hope to god you dont think N/A originated on IA, or in the import world at all for that matter...

Perhaps "All Motor" is the term you are looking for.