Though the series is about kids in middle school, many of the cast members, guest stars, and extras were much older and were High School aged, not Junior High aged. In fact Nick Spano is supposed to be High School aged but was actually in his late twenties and early thirties during the run of the series.
In the pilot episode, whenever a character says the name "Stevens", the audio doesn't match up with the visual because the original name was Spivey.