Victor Buono played Reverend Jim Ignatowski's father, Mr. Caldwell, despite being only ten months older than Christopher Lloyd.
Nominated for the 1980-81 Emmy for Outstanding Writing in a Comedy Series
It is revealed that Jim's last name was Caldwell. He changed it to Ignatowki because he thought it was "star child" said backwards.
If you go by the actor's ages, not only is Iggy the same age as his Dad, but Mr. Caldwell would have had his other kid's at the age of 9 and 10.