1FZFE VALVE SPRING & RETAINER KITS Designed for high rpm BC valve springs by PAC Racing are wound from only the highest grade super clean chrome silicone alloy and feature proprietary processing procedures for consistent pressures. BC titanium retainers are CNC machined from 6AL4V round bar titanium to exacting tolerances. For more information visit http://www.briancrower.com/makes/toyota/1fzfe_valvetrain.shtml