This emblem was used for one year only, on the 1966 Corvette. The Big Block first appeared in the Corvette in 1965 as a 396; the '66 Vette's had the 427 in either 390 or 425 horsepower version (although a few early 425 horse models were rated and badged as 450 horsepower). The 427 lasted through the 1969 model year, and in 1970, it was replaced by the 454. But it was the 427 that established the Chevy Big Block as the bad boy of the street.
Lost in the recesses of my mind is a vague recollection that small block Chevy's were all called Turbo-Fire's and big blocks were called Turbo-Jets.