Pettite finished his career 102 games over 500, at 240-138, a very good record.
Whitey Ford made it to the Hall with only 236 wins. The thing with Whitey, is that he had only 106 losses, and a much better ERA than Pettite. Pettite's career ERA was 3.88, Ford's was only 2.75.
With five man pitching rotations, the Hall may have to lower it's standards for starting pitchers to get in, such as using ERA, strikeouts, etc, instead of "The guy must have 300 wins to qualify". With less decisions, a guy with 250 wins.. who is say.. 100 games over 500 for his career, with a good ERA of around 3.00 or so, should probably merit consideration.
Very few pitchers in modern history who pitched in five man rotations their whole careers, ended up with 300 wins. The only four that come to mind are Glavine, Maddux, Randy Johnson, and Clemens. The first three are no brainer first ballot Hall of Famers. Clemens? Well.. we all know about him.
Some of the 300 game winners in the 60s and 70s spent time in four man rotations for a time, including guys like Niekro, Seaver, Ryan, etc.
Pettite was a very good pitcher. His record is fine, but his ERA to me seems high for a Hall of Famer. I think he might fall short.
Mitch