Valve Covers - To vent or not to Vent

[tsmith8]

I currently have a generic set of valve covers on my 327. They are vented into lines that terminate at the base of the firewall. (Not my setup, but just how it has been since i bought the truck)

I found another set of valve covers in my garage that i like better. They are not vented.


So the questions is:
A) Am i going to effect anything by having none vented valve covers?
B) just an FYI i have a vented oil fill tube.

[PDW HOTRODS]

The oil fill in the front of the intake like factory with a vent would be fine. Thats the way they were originaly. The breather in one valve cover and pcv in the other are probably better, but were done more for emissions. With only the one vent and no pcv, you may get a little oily mess at your vent. There is air pressure in the engine, more if the engine is tired and you have blow by by the rings.

[mr48chev]

That really sounds like a hinky home made road draft setup that probably doesn't work all that well to begin with.
The standard (now days) breather in one cover and pcv valve in the other with the hose running to the carb or intake would work lot better.

[59chev]

With any crankcase ventilation system you need an air and an air out. Your vented fill tube can work as the air in but the air needs somewhere to go out. An early 327 ( 62-66 ) has an extra hole cast in beside the distributor where an pvc valve can be hooked up. A later 327 ( 67-69 ) is the same block as the 350 and relied on vented valve covers.