Untold Tales #405 Justice League of America and Captain America

Cap seems like a natural to join the Silver Age League, doesn’t he? And I doubt he’ll have any trouble dealing with the Injustice Gang.

Mash-Up #293 Justice League of America vs Sinistro, Boy Fiend

It’s back to the 60s for the JLA as they go up against one of their mightiest foes . . . er . . . some kid who got powers.

Sinistro, Boy Fiend, was a short lived character from Charlton comics whose secret identity was the wonderfully named Jack Biceps. He also, judging by the posture on the cover above, had a really bad back problem.