The Chevrolet Camaro ZL1 package was available with an all-aluminum 427-cubic-inch V8 in 1969.
Chevrolet developed the ZL1 engine for racing applications. It was based on the big-block 427 but used an aluminum block, helping reduce weight compared with an iron-block engine. The engine was installed in a very small number of 1969 Camaros ordered through Chevrolet’s Central Office Production Order system.
The ZL1 Camaro was built for serious performance rather than ordinary mass-market use. Its engine was related to Chevrolet’s Can-Am racing technology and was officially rated at 430 horsepower, although contemporary discussions often cite higher potential output.
The ZL1 name is sometimes confused with Z28, another Camaro performance designation. Z28 identified a different package centered on a 302-cubic-inch engine for Trans-Am racing eligibility.