The issue was that the small-block Chevy ... Am 427 big-blocks were the most successful versions of the all-aluminum big-block configurations for racing. The ZL1 made its debut on the cover ...

The Chevrolet big ... valve heads, more commonly called porcupine heads for the differing valve-stem angles you see with the valve covers off. Chevy built both a 409 Mark II, and a 427 Mark ...

By 1961, the Chevy engineering team in charge of developing performance motors faced a new challenge. The Mark I (W-series) big block ... of how the valve stems looked when the covers were removed ...

The issue was that the small-block Chevy ... Am 427 big-blocks were the most successful versions of the all-aluminum big-block configurations for racing. The ZL1 made its debut on the cover ...