What is the hose coming out of top passenger side valve cover - opposite from PCV leading to air intake line on Chev 5 liter V8?

That hose on the passenger side valve cover of a Chevy 5.0L V8, opposite the PCV valve, is usually a crankcase ventilation hose or part of the positive crankcase ventilation (PCV) system, but it *doesn't* directly connect to the intake. While it's part of the overall system for removing crankcase fumes, it often leads to a different location than the main PCV hose. Its destination depends on the specific year and engine configuration.

Possible destinations include:

* Air cleaner housing: This is a common location for a secondary crankcase ventilation hose. It allows crankcase gases to escape into the atmosphere after being filtered, but before reaching the intake.

* A separate vent: Some systems may have a separate vent to the atmosphere, often routed through a charcoal canister or filter.

* Oil separator: Some newer engines might use an oil separator to reduce oil mist from entering the intake. This hose would then connect to the separator, which in turn connects to the intake.

Without knowing the exact year and model of your Chevy 5.0L V8, it's impossible to say for certain. Checking a repair manual specific to your vehicle's year and engine code is the best way to confirm its purpose and routing.