[markjohnson]

Such special cars that carry the overlooked distinction of being the first Chevrolet product to carry that magical 427 displacement number, even though the bore/stroke slightly differed from the soon-to-come MKIV (4.31 x 3.65 vs. 4.25 x 3.76). To me, there four ultra-compression factory Chevrolet racecars: the 1963 Z11 Impala, the 1969 ZL1 Camaro & Corvettes, and the 1967-69 L88 Corvettes. All these cars had 12:1 compression or higher. That’s less than 350 cars, being quite generous with the mysterious 1969 ZL1 Corvette production numbers. Sure, it could be argued that other cars were factory drag cars (like iron block COPO’s or ‘63 Z06 Corvettes) but those were lower compression cars that were quite streetable & didn’t demand special fuel like the cars I listed above. BTW, the ‘63 Z11’s have a very low survival rate with approximately 17-18 survivors of the 50 produced.