I thought that might be what he was getting at, but the whole "filler tube" part kinda threw me, for some reason. If the oil you're pouring into your motor is so lumpy that you need a filter on the filler neck to keep the chunks out, I think it's time to switch brands.
summit has them as well, they have them with a ford logo... i ordered one when i was having problems with pressurizing my crankcase and kept blowing out my upper to lower intake gasket at the back. unless your forced induction theres not really any point to having one