GSC Power-Division Single Valve Spring Kit for FA20 WRX-BRZ-FRS CDI Systems We introduced the high efficiency

We introduced the high efficiency 4-1 as against the STD 4-2-1

This Block Is Our Base Non Closed Deck (Semi Closed) EJ257 With Forged Internals

the single bearing design is not ideal from a durability standpoint

Impreza STI 2004-2018

GSC Power-Division Single Valve Spring Kit for FA20 WRX-BRZ-FRS CDI Systems We introduced the high efficiencyMax RPM: 8,200 RPM Max boost: 20 psi Cylindrical Spring Coil Bind 0. 782 Install Height 1. 294 1. 298 Seat Pressure 86 25 lbs Open Pressure @ 11. 0mm Lift 179 lbs @ 0. 861 178 lbs @ 0. 865 Maximum Valve Lift 0. 452 Includes: 16 Dual Springs 16 Spring Seat Locators 16 Titanium Retainers