Ford 4.6L 5.4L 4-valve Valve Spring Compressor Tool Mustang Cobra GT GT500 Install valve spring/retainer/keepers easely and quickly CNC machined 6061-T6 Aluminum body Anodized finish Made in the USA 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.