TOMEI VALVE GUIDE SET For SILVIA S14 S15 SR 163049Brand TOMEI Product Number 163049 Compatible Car SILVIA S14 S15 Compatible Engine SR Product Description We chose to use Phosphor Bronze (Cn Sn P alloy) to make our Valve Guides, for its highly tensile and superior heat transferring ability, which is vital in high power and high RPM outputting engines. Since race engines these days require more power at higher RPM use, these engines now experience more extreme heat conditions. These conditions will