The late Royce D. (no relation to Christina) Applegate went on to star as "CPO Manilow Crocker" on the TV series SeaQuest DSV which also starred another late great, Jonathan Brandis. Interestingly, Royce was born on Christmas Day 1939 and died on New Year's Day 2003...
...Ronnie Troup is the daughter of late Emergency! stars Bobby Troup and Julie London.
This two-parter was actually the last episode taped for the series. Supposedly, the Drummonds are renovating the penthouse; actually, the set was being torn down while they shot.
As was phased in last season, the emphisis now is more soley on Arnold and/or Sam, with some characters, such as Willis and Pearl, being seen less regularly.
The original theme tune, used from the 1st season up until the last, is replaced with an updated version. This is due to NBC owing a copyright to the original, so ABC was forced to create a new one. The closing credits also have a new, synthesized version.
Mary Ann Mobely took over the role of Maggie from Dixie Carter, the only character in the show's eight-year run to be re-cast.
Ironic that Different Strokes joined the same network which also showed Webster, which basically stole the same idea of a pint size adopted kid from Different Strokes. Webster also did better in the ratings as well.
With this, the final season, the series moved from NBC to ABC.