I have a 03 Lightning myself and found the PCV valve on the passenger side valve cover. I don't have any problems or anything but wanted to say that, with supercharged engines, you would hope that the PCV valve itself is a bi-directional unit.

Otherwise, unless you have an oil recovery system, there would be MORE oil comming up into the intake than normal. A normal ammount is just a slight sheen coating of oil inside the intake and around the throttle body.

Motorcraft EV-233 PCV valve is stock on the 03 Lightnings and IS bi-directional. They also come with a 45 degree boot that you can take off. I installed PCV valve w/45 degree boot and it does calapse. Just remove the boot and install it straight up (2003 Lightning here) and all is well.

King Leo