IIRC, the '350SS' was a dealer option prepped by an aftermarket co. for GM. Kinda like the '4X4XKERR' 4 whl. dr. vans of the late '70's/early '80's. They weren't made by GM, but they were offered by the dealerships, in order to cash in on the 454SS's popularity, but without the lousy gas mileage. Basically a W/T with a set of aftermarket body side mouldings (no logos in the mouldings on the doors) a set of chrome deluxe bumpers, and the stickers, which were usually applied at the dealerships. The stickers were sent with the trucks, & installed by the dealership as part of the 'Dealer prep'. That prep charge appears on every GM build sheet, no matter what the vehicle.
Due to the fact that the stickers were applied by the dealership, slight variances in the positioning of those can be apparent when comparing 350SS's against each other. The option may or may not appear on the option list in the glove box.
The trucks came with the SS wheels, not the ones in that pic.
Can't remember if they had a 2/4 drop like the 454S's. That one kinda looks like it has that mod. They definitley did not have the 14 bolt rear end.