During Howell's seven seasons as head coach, he earned a career 53–27–4 record, with a .663 winning percentage. He drafted and coached a roster of stars including six future Pro Football Hall of Famers, Sam Huff, Andy Robustelli, Rosey Brown, Emlen Tunnell, Frank Gifford and Don Maynard. Although his conservative, defense-oriented style was unpopular with the fans and media, the Giants' success on the field was more satisfying. Several other players from this era went on to become head coaches and broadcasters.
Howell played and coached in an era when football went from a relatively simple game to one of great complexity with schemes, formations and playbooks designed to deceive as much as over power. With future Hall of Famers Lombardi and Landry as coordinators, Howell's job was frequently to play the diplomat within his own team.
Howell stayed with the team as Director of Player Personnel until his retirement in 1981. He died on January 4, 1995 in Lonoke, Arkansas.