COMP Cams Hi-Techâ„¢ Oil Restricting pushrods feature 0.050" oil holes, which are half the size of standard Hi-Techâ„¢ pushrods. These pushrods maintain the consistent Hi-Techâ„¢ Pushrod features, including one-piece 4130 chromemoly, heat-treated steel material with a wall thickness of .080" and a 60 Rockwell hardness. To avoid confusion, each oil restricted Pushrod is clearly labeled with length and diameter for easy identification. For each engine platform COMP Cams offers five different Pushrod lengths to meet any need.