After Officer Dan mentions that Jefferson was named after a U.S. President, Ike tells Jefferson that he thought he was named after Sherman Hemsley, which appears to be the real truth according to Jefferson who didn't deny Ike's statement, but simply shrugged. However, Ted McGinley was born in 1958, nearly 17 years BEFORE the pilot episode of The Jeffersons (1975). Therefore, his character Jefferson D'Arcy who is approximately the same age, could not possibly be named after George Jefferson.
Griff tells Al that he never liked Psycho Dad, but in Part 1 Griff was wearing a Psycho Dad hat just like Al and Bob Rooney when he came over to Al's house to complain about Psycho Dad being canceled indicating that he was a fan of the show.