How Horsepower Works Answers that Question The 1969 Yenko Chevrolet Camaro 427 was the delicious conversion of muscle car need and a factory's desire to please. To Ford fans, Carroll Shelby is the high-priest of performance. Chevy loyalists revere a Canonsburg, Pennsylvania, car dealer named Don Yenko. Yenko had a deserved reputation for driving, building, and selling dominating Chevrolets, starting in '65 with well-crafted super Corvairs. He advanced to installing 427-cid Corvette V-8s in '67 and '68 Camaros, performing 118 of the transplants. These $4,200 ponys ran in the low 13s right off his shop floor. But Yenko Sports Cars Inc. had dealer outlets for its cars in 19 states, and that earned clout with Chevrolet. Dealer conversions were complicated, however, and came with only a limited engine warranty. So at Yenko's urging, Chevy agreed to factory-build a batch of 1969 Camaros with 427 engines, and to provide full 5-year/50,000-mile warranties. This was done under the Central Office Production Order system, which had previously been used to satisfy special requests from non-performance fleet buyers. How many COPO Camaros were built isn't known; Yenko ordered 201, but other dealers could order them as well, and 500 or more were produced. All were basically the same: They had the iron-block and head, solid-lifter L72 427, which Chevy pegged at 425 bhp but which Yenko rated a more-realistic 450; Hurst four-speed manual or dual-gate automatic; heavy-duty 4.10:1 Posi; cowl-induction hood; heavy-duty Z28 suspension with F70xl4 tires; and other go-fast goodies. The package added about $800 to a base coupe, including $490 for the engine.