IROC and ZR-1 motor question

[Terry24]

Greetings all. A guy I work with bought a few years ago, a red 1987 IROC Camaro, off of a flight attendant. She sold it to him because "it was too powerful" or something like that. She told him nothing was ever done to the car, modificationwise. After he bought it, he took it to the local Chevy dealership and they discovered it was the wrong motor. The motor that was in it was the Corvette ZR-1 motor, so he contacted the flight attendant back and she clamis that it was stock.
Ok, so assuming that everyone is telling the truth (doesnt everyone??), is is even remotely possibly for the factory, or an excutive, make such an order when ZR-1s didnt come out for a few more years?