Brand New Lunati .660" Max Lift Hydraulic Roller Dual Valve Spring Kit for a GM LS-Series V8 Engine (LS1/LS2/LS3/LS6/LS7). 8mm Valve Stem Size, 7º Lock Angle, Single Valve Groove Type. Kit Part #73925K1. Kit Includes: #73925-16 Dual Valve Springs (Specs below) #75793-16 Retainers #77123-16 Valve Locks #86873-16 Spring Seats. Valve Spring Specs: Outside Diameter (Outer): 1.306" Inside Diameter (Inner): .676" Max Lift: .660" Seat Load: 153 @ 1.810" Open Load: 400 @ 1.150" Coil Bind: 1.100" Spring Rate (lbs/inch): 379 lbs/in Racers and engine builders of LS Series GM engines now have a brand new, extreme usage (.660" Max Lift) Valve Spring, Spring Retainer, Valve Lock and Valve Stem Seal Kit that safely extends engine RPM and boosts performance capability with normally aspirated or power-added LS engines. Lunati’s new kits feature precision wound, heat-set, dual valve springs, for required seat and open-load pressure plus total spring travel to accommodate cams with aggressive gross valve lifts of up to .660”. The valve springs in each kit are carefully tension matched and all supplied components come complete and ready to install. Included are Lunati’s CNC machined, steel alloy spring retainers, CAD designed to deliver maximum strength and durability. Precision fit spring locators are also included, and are cleverly designed to accurately locate the inner spring, preventing abrasion with aluminum LS Series heads. Precision-machined steel alloy 7-degree valve locks are also provided, for superior valve stem holding reliability. Premium quality, Viton steel reinforced valve stem seals are included for correct valve stem lubrication and oil control.