I have recently found a 84 442. Everything on the car from engine to stock airs hocks and 200r4 trans is correct. All the badges are where they should be and under the head the header tags specify that the car is equipped with the 5.0 . I ran the vin numbers and the vin comes back as a 3.6 special coupe ( T-tops) . So I got thinking about the Yanko Cameros and even a Dealer built Silverado that my brother had ... when you run the vin on his truck it comes back as a 5.0 Silverado in plain trim but the truck was sold NEW with a 383 and many Dealer installed factory custom parts. So is it possible that in 84 dealers or a dealer built and sold 442s ? Now the car could be a fake but it had to be built around the time when it was new which is why I am at a lost with this car.

 

Is there a RPO sticker anywhere on the car that lists all of the options? On the '86 it is under the trunk lid but the 84 may have it elsewhere.
A clear photo of that could help.

 

First, the 383 was never a factory engine option and Chevy engines were never installed in a 442. Second, the 442 decals didn't exist until the 1985 model year. Third, unlike the 1970s, in 1984 it was (and still is) against the law for a dealer to install a non-emissions-certified engine and sell the car to the public.

That sound you hear is the BS detector going off.

Somebody is "yanko-ing" your chain (it's YEnko CamAro).