Kevin,
I don't think that a filter was stock...
With that said...hanging off the manifold is where I would put mine. My Fram was hanging there when I got my truck.
There is a pic (should be called C20) in my webshots account.) I have not put my filter back on yet. Still planning a major tear down in the fall so I hate to put it on only to take off.
Fram mounts with two U-bolts....
