Chevrolet's Central Office Production Order (COPO) system was designed for fleet sales; it was intended to spec out heavy-duty suspensions for cop cars and stain-proof interiors for taxicabs. But enterprising dealers with the right connections, such as Yenko Chevrolet in Pennsylvania, figured out that Camaros could be ordered this way, too. And given the right order codes, the dealer could spec out a fire-breathing monster of a Camaro that Chevy didn't really want you to own.
The production order 9561 specified a 427 big-block V-8 rated at 425 hp—just like a Vette. But the even rarer COPO 9560 called for an all-aluminum ZL-1 427 V-8. Though this engine was rated with just 5 more hp, it was widely known that this race-spec engine delivered more like 550 hp. Only 69 ZL-1 Camaros were built, and these cars command prices in the $400,000 range at an auction
Little-Known Fact: The aluminum ZL-1 427 V-8 in the 9560 COPO Camaro is essentially a race engine. Chevy originally developed this 427 motor for the Chaparral racing team to use in the Can Am series. There are no external emblems on a ZL-1 Camaro that let you know what's under the hood—only plain-vanilla Camaro badges.