Yes, that's correct.Round motor for concealed, square motor for standard?
Correct. One is for hidden, one for non-hidden. Here's a thread I used to help me when converting the non-hidden wipers on my 73Z to hidden.I think the arm that attaches to the wiper motor is specific as well.
From the GM Heritage center:NOTE: Concealed, hidden, depressed are all terms for the same thing. The wipers tuck under the hood ledge so you can't see them. I don't know what term GM used but it's a PITA to have different ones. Perhaps someone can show some documentation on which term GM used. It's probably in my parts catalog or service manuals, but I can't look it up right now because I'm supposed to be working, lol.
EDIT: Oh, and "parked" may be another term.![]()