I have seen it done first hand, i worked for an Olds/Buick dealer. It was done on new and used 442 even a plain cutlass per the customer even the air dam was installed its was all about sales. It wasn't just installed on the 87, even 85-86. It was popular back then. The owner of dealer had two new 87 442's setup with hood scoop, wing, air dam and lighting rod shifters i had installed the shifters , they where put on the lot and they sold.It's entirely possible it was dealer installed. I'm just wondering if anyone has ever seen this done to a 442?
I would recommend removing the hood insulation and see if they had blocked the hole that was used for the center hood trim, if not blocked its possible you will have water entering the engine compartment.
83-84 hurst hood didn't have that extra hole in the hood for the center molding and had a different part number than a regular cutlass.