I'm rebuilding an SR20DET that I purchased while it was unassembled. I have a quick question about the oil tubes that bolt on with the cam shaft bearings. I've watched a few videos of the process on YouTube. I noticed that in the videos, each oil tube also had a metal piece that bolted on with it. Sort of like a small shield. I don't have those pieces. I only have the oil tubes. I've seen some images online, that also show the oil tubes installed without the metal pieces. Do I need those metal pieces, or can I just install the oil tubes without?