Hi, Garg - I thought the same, but there have been Chevrolet engines in that range. Here's a Chevy engine with a 572 cubic inch displacement:

https://www.chevrolet.com/performance-parts/crate-engines/big-block/zz-572-720-r

And there are Corvette gullwing doors available as custom aftermarket equipment. My wife's previous husband was a very good friend of mine, and I got married to her about a year after he died. He had a Corvette that he just loved, and it was just beautiful. His kids inherited the car when he died, and they sold it. It was a beautiful thing, and its engine was huge. It drove like a truck, but it sure could go fast. Not my kind of car, but it was a work of art.

I think McCutcheon meant the gullwing doors and engine displacement to be hyperbole.

-Joe-