Ford Modular 4.6L 5.4L 4V Valve Spring Compressor Easily install valve springs and retainers. For use on all 4.6L/5.4L 4V Cylinder Heads including Cobra B and C Heads, 03/04 Cobra and Mach 1, Navigator, Ford GT / Shelby GT500 and FR500 Cylinder Heads. Made of anodized 6061 aluminum. Made in the United States.