Lash adjusters in Ford Modular engines can leak down under high RPM, causing lost duration and lift, as well as increased valve train wear. The COMP Cams Ford Modular Performance Lash Adjusters are engineered to have a slower bleed down rate compared to stock lash adjusters. The slower bleed down rate ensures valve motion more closely follows the camshafts, with less duration and lift lost at high RPM/load. Because they bleed down more slowly, COMP Performance Lash Adjusters provide far better valve train stability and high RPM durability. Built for durability, COMP Cams Performance Lash Adjusters feature a black oxide to prevent rust and corrosion.