"Ralph vs. Potsie"

This is one I sort of remember from the time, especially the Bradyesque line down the middle of the room.  Some of the humor here, like with "Fat Phyllis's dress," is corny, but it works, so B-.

A few notes:

• Chachi is back, I think for good, and somewhat impacts the plot.  Not coincidentally, Baio is now in the opening credits.
• Richie was editor (or at least science editor) of the college newspaper recently, but here he's writing an advice column in a shopping paper for a couple weeks (while "Aunt Fanny" is away getting a divorce).  I'm not sure if this is an improvement or not, although at least he's getting paid.
• And, yes, the trope of someone being an anonymous advice columnist and giving bad advice is friends is fairly common, but I've always been fond of it.