The most "significant" Chevrolet performance car.

[ohhawk]

I think you would have to throw the following into the hunt as well........

http://www.57chevyblackwidow.com/guide.html

"most significant performance car" I think would have to be the Corvette. Maybe not always the fastest in a straight line from point A to B but performance is more than straight line speed. It still exists as an icon for performance after most have folded.