Comprehensive cylinder head valve train kit which provides robust upgrades to 5.2L cylinder heads. These components were fully developed for and used on Ford Performance FP350S road race car, capable of race duty, and 8,250 rpm. Includes: 16) Solid steel, 1.51 in intake valves 16) Solid steel, 1.28 in exhaust valves 32) Stiffer, unique valve springs from PAC® 64) Valve spring keepers/keys 32) Titanium valve spring retainers 32) Valve stem seals Note: Titanium valve spring retainers require routine replacement, normally after after each race season.