The only other application I can think of may be a 1967/68 Impala.
I did a engine rebuild on a 1968 Impala SS-427 'California Car' quite a few years back and it had some 'odd' covers on it that I send out to re-chrome - passenger's side had that K19 diverter valve mount on them ...
It also had a couple small 'dinks' to clear the AC Compressor bracketing system, but I really don't recall exactly how many or where they were located
- just remember thinking 'oh, that's why those are there'
as I put it all back together. (I didn't take it apart - PO had ...)
I took pictures of the block, long-block and a few other things while doing the work back then - but a quick look through some of my slides (
it was that long ago
) didn't show any photos of the finished passenger side that showed covers detail.
To bad there's no identifier decal on one of the ends ...
I can't remember any Chevelle applications like that.
And that Impala would have to be my best re-collection
- and I'm old
Sooooo ... if JohnZ can't identify them then I'm afraid you quest for their OEM application must continue