This was the episode being filmed when John Lennon and his son Julian Lennon visited the Happy Days set, resulting in a now widely-circulated photo taken with the cast of the show.
Fonzie wears his leather jacket for the drag race for the first time.
Ralph says Skizzie's girlfriend Jean looks like the actress Annette Funicello. He is right. She is a dead ringer for what Annette Funicello looked like as a teenager.