Dick Tracy vs FlatTop was a story consisting of several long chases which lasted from December 1943 to May 1944. This is considered one of the longest strip stories ever.
I can't find an exact date for Flattops first appearance, but sometime before December 1943 and it ran to may 1944. Undercounting the sundays as only one panel, that's 180 panels+. What the whole sage would run to in panels, I don't know.
https://en.wikipedia.org/wiki/Flattop_(Dick_Tracy_villain)
Gould also kept coming back to it, creating Flattop Jr, Blowtop, Daughter Angeltop, grandson Hitop, identical twin Sharptop, Father Poptop and
Stilleta "Mrs. Flattop" Jones - The widow of Flattop Jones and the mother of Flattop Jr. and Angelica "Angeltop" Jones and a former circus performer bent on revenge for the deaths of her husband and children.
and a couple more.
When you're on a good thing, stick to it!