On a factory 87-93 Mustang 5.0 the passenger side valve cover is supposed to have a breather port that connects to the intake elbow. And there is no PCV port on either valve cover. The PCV valve is on the back of the intake manifold.
I would not recommend those valve covers for a classic mustang with a carburetor type intake manifold.
yours are on backwards ,is your filler on the right rear cover ?Might I suggest the "other" fox body valve covers? I love mine and you don't have the filler tube/PCV issue.
Backwards according to stock application, not according to my setup. As you can see, the PCV connection is on the front side of the carb. The breather is in the back on the passenger side. I pop out the PCV valve to fill the oil. It's super easy.yours are on backwards ,is your filler on the right rear cover ?