My DS1S isn't a huge fiction fan either. Particularly when he was younger but it's grown on him and he now appreciates it as long as he doesn't have to analyze it.
If your son likes historical fiction has he read any Richard Peck? Most of the books are a 4th-6th grade level, but many of them are historical fiction about new technology. My son did a 2nd grade report on one of his books. The project was to do a report based of a historical fiction but he was reading 2-3 grade levels above most of the kids. Most of the kids were doing American Girls or Magic Tree House. My DS read The Teacher's Funeral as a good compromise between too easy vs too hard/long and a subject matter than interested my son.
