Cameron Gellman (Hourman) had to pull apart metal bars during a scene with the JSA. He kept struggling with it and couldn't pull the bars apart despite having trained for it. The crew told him to "put his back into it" but he still wasn't able to bend them. The crew decided to try and when they failed, they realized they forgot to put the hydraulics at the top of the bars, so Cameron was trying to bend real metal poles.
Henry Sr. mentions that his wife' name was Merry. In the comics, Brainwave's wife was Merry Creamer, who was adopted by Sylvester Pemberton's parents. She eventually became a non-powered superhero, known as Gimmick Girl and Merry, Girl of 1000 Gimmicks.
Prez, Unknown Soldier, and GI Robot are displayed as movies on posters outside of the town theater. All three of these are minor DC comic book characters.
The movie theater seen in the opening scene is playing a movie called Strange Adventures. This is the name of comic book published by DC.
When looking at the pictures of the Seven Soldiers of Victory, everyone comments about how there are eight people in the photograph. In the comics, the Crimson Avenger's sidekick, Wing, was not a member until the Crisis on Infinite Earths. After the Crisis, Green Arrow and Speedy were removed from history. Wing and Vigilante's sidekick, Stuff, were retroactively made members.