A GM corporate edict forbade Chevrolet from installing engines larger than 400 cu in (6.6 l). However, two Central Office Production Orders (COPO) 427 cu in V8 engines, numbers 9560 and 9561, were offered from dealers in the 1969 model year of the Chevrolet Camaro. COPO 9561 used the solid lifter L72 big-block engine, making an underrated 425 hp. COPO 9560 used an all-aluminum big-block called the ZL-1 and was designed specifically for drag racing. It was the most powerful engine offered in the 1st generation Chevrolet Camaro (1967-69). Though rated at 430 hp (321 kW) gross, the ZL-1 made 376 SAE Net hp in its "as installed" state. With exhaust changes and some tuning, the horsepower jumped to over 500. Just 69 ZL-1 Camaros were produced. (wikipedia)
(Photos from boldride.com & autowp.ru)
