In the late '70s I meet a guy with a '68 Dart GT with a factory 340 6Pac. He said he bought it off the showroom floor that way.
He Lied.
I also knew a guy that had a '62 Corvette with a "283" that could blow the doors off just about anything. Fastest "283" that I ever saw.
Seen some fast 283s.
Stories are told, sometimes they are true.
