The Camaro ZL-1 was a high performance version of the First Generation Chevrolet Camaro. In 1969, in order to circumvent General Motors' engine size limit for mid-size and smaller cars, Chevrolet created two Central Office Production Orders (COPO). The first was number 9561, which gave the Camaro a 'L72' 427 V8 engine; these cars are commonly known as the COPO Camaro. The second COPO was number 9560, which was the ZL-1 Camaro. The ZL-1 was a 427 cubic inch V8 engine with an all aluminum block created specifically for drag racing. Only 69 examples were fitted with the ZL-1 engine, making them some of the rarest and most sought after Camaros in the world.