Competition Cams 26113-16 Beehive Valve Spring for Ford 4.6L and 5.4L Modular 2 Valve Engines Seat pressure: 93 lbs. @ 1.570 inch, Open Pressure: 198 lbs. @ 1.020 inch O.D.: .959 inch (Top) 1.061 inch (Bottom), I.D.: .636 inch (Top) .738 inch (Bottom) Designed for Ford 4.6L and 5.4L Modular 2 Valve engines .550 inch maximum lift, 1.061 inch O.D. No machining required