Having owned a 409 Bel-Aire, the 0-60 time was in the mid-6 second range as I recall. The problem was that the narrow bias ply tires of the day did not have the grip necessary to take full advantage of the 409's torque. Now, if you had slicks on the back it was a different matter altogether. In fact, if you were inclined to drag race one of these things, you would use sheet metal screws to screw the tire bead to the wheel rim because the car was capable of turning the tires off the rims.
Mine was a sleeper. Actually all 409 Bel-aires were sleepers because the didn't have all the flash of the Impala SS. It was painted all over with that ubiquitous metallic blue that Chevy had, painted steel wheels, and dog dish hub caps. I ran wider than stock wheels in order to get as wide a tire patch as possible. The car defined the meaning of understeer. It did, however, keep me well supplied with beer at the unofficial Friday night beer drags when I was in collage.
My cousin owns a 1964 289 FIA Cobra, not as fast as the 427 Cobra, but quicker than a 409 because it was considerably lighter and made about the same horsepower. And it handles, not one of the 409's virtues.
