World Products is familiar with making high-quality parts, and their CNC die-cast aluminum valve covers are no exception. Their die-cast aluminum construction doesn't rust like steel, is excellent at dissipating heat, and makes bent gasket rails a thing of the past. They have a tall design to clear roller rockers and stud girdles, and a polished finish with your choice of CNC-machined Merlin or Hardcore logos. Each cover has one 1 1/4 in. hole for breathers or PCV, and reinforced flange areas around each bolt hole for added strength.