Car and Driver spent the 1960s testing everything from factory Corvettes to a road-going Ford GT40, all reduced to the same simple number: 0-60 mph. Two Shelby Cobras claimed the top two spots, one of them clocked at a scarcely believable 4.3 seconds, while a small-block Mustang GT snuck onto the list ahead of genuine big-block muscle. Read on to see how all twelve cars stacked up — and why the testing methods behind these numbers deserve an asterisk.