Can I simply bolt a nitrous kit onto my stock engine?

Yes.  The key is to choose the correct kit for a given application; i.e., 4 cyl. engines normally allow an extra 40- 60 HP, 6 cyl. engines usually work great between 75-100 extra HP, small block V8’s (302/350/400cid) can typically accept up to 140 extra HP, and big block V8’s (427-454) might accept from 125-200 extra HP. These suggested ranges provide maximum reliability from most stock engines using cast pistons and cast crank with few or no engine modifications.