GSC Power-Division OEM Replacement Valve Spring Seat Set for 4G63T (gsc1004) StillenShipping_45 RD testing has shown this

RD testing has shown this system flows up to 288 cfm more than the factory exhaust

the shoulder part and the door may interfere

50 female fittings on same side (feed and return w/ 40-degree angle)

If you're purchasing a new Ford Focus RS

Direct Replacement for P/N 05-01492

GSC Power-Division OEM Replacement Valve Spring Seat Set for 4G63T (gsc1004) StillenShipping_45 RD testing has shown thisGSC Power Division OEM Replacement Valve Spring Seat Set for 4G63T. Perfect for replacing old seats when upgrading to a high performance spring kit like the GSC Beehives. Same thickness as OEM, so no spring pressure change when using these. Sold as a set of 16. Features: Made 100% in the US Designed to deliver trouble free, consistent performance Right for your vehicle and lifestyle Made from high quality materials for ultimate durability Manufactured