Dress up your Hemi engine for that custom look with our new Hemi Deco polished tubes covers. These tube covers have a threaded base that simply screws on top of our Billet tubes. They are Awesome looking and they keep water and debris out of your tubes. Note: Fits Hitech spark plug tubes only. Available in three different styles. Please note Mopar Logo tube cover is not available for sale. HRS6 Smoothie. HRS7 Twister. HRS8 Torquer.