Into the inner debpts I go. The cam and lifters are hidden by the oil shield. It keeps hot oil off of the bottom of the manifold. L88 stuff, you know. Also note the center passage for carb heat. After 36 years it's cleaner than the area under the valve covers. These are 'off road only' heads. There is no passage cast for heat to the carb. That makes for a denser fuel charge but the divorced choke never heats up. Of course that helps the oil shield do its job. Now with fuel injection, the engine loves it.