Below are some codes that might possibly be found on your body tag, as well as the build sheet (look under the seats, stuffed into the seat springs, behind the seat, under the carpet, etc.).
Build Sheet Numbers
B22 Door trim pad emblem " SS "
PM7 F60-15 White letters, SS models. (also Sprint SP models).
X11 Style Trim for base car or SS
X22 Style Trim for SS with 396
X55 Base SS with 350
X66 Base SS with 396
Z27 SS equipment
Z15 SS equipment. (454 in '70)
Cobalt, did you miss the fact that this is a 1979 Elky?, there wasn't a BBC in sight for about 5 years by then, this is a metric chassis. I'm not sure there is any vin or code tag info that will indicate a true SS in these cars. By this point in time, it was pretty much just a "sticker" SS, an appearance package mostly.
I'd try a Monte SS message board or forum as they tend to include these cars.
I own an '80 Malibu, so yes, I'm aware of the engines that were available in them.
These are all of the "SS"- related codes I could find, I made no delineation as to year or engine size. This is to help ID an SS- any year, not just the OP's '79- should anyone do a search for "ID 19xx SS (El Camino, Impala, Nova, etc.)", for instance.
The list is not complete and does not contain all codes that might pertain to a SS car. However, if a car has any of these codes, it's one indication of it being an authentic SS.