With steel top & lower collars. Reduces total valve train mass. Great for stock & moderate performance builds. The one-piece Beehive style springs are manufactured from the highest quality clean chrome silicone wire, shot peened and heat treated for maximum fatigue life. Kit includes steel upper collars, lower collars, valve keys and seals. Works with stock 7mm valve stems. Max valve lift: .660". Installed height: 1.860". Seat pressure 178 lbs. Open pressure: 371 lbs. @ .660" valve lift. Note: See 524994 for replacement valve seals.