Hello Summertime, I have a 68 327/275, am the original owner, all original components. The oil filler neck is the kind John Z described, with the PVC outlet (plugged) and indented cap. This is the original filler and cap. The interesting thing about it is that it was painted orange new( and still is) but under the paint it is chrome! Have had many people tell me its wrong, should be black, with flat cap, and so on. Then I show them the invoice. By the way, my car is a late car, built in june of 68. Hope this helps. C