Tri-Y Design: Paired opposite firing cylinders with equal, specifically tuned primary lengths maximizes scavenging and increases torque throughout the power band. 304 Stainless Steel Laser Cut Header Flanges: High quality laser cut 304 stainless steel header flanges provides superior sealing at the head surface. 304 Stainless Steel Tubing: High grade stainless tubing with a uniform brushed finish provides a beautiful look and high resistance to corrosion. TIG-Welded: 100% TIG-Welded by certified craftsmen for race proven strength and durability. TIG-Welding provides the strongest welds reducing stress cracks. Factory Mounting Locations, 2.5" Inlet/Outlet Connection Pipe mount directly to OE mounting locations. Mandrel Bent Tubing: This system is constructed of mandrel bent, stainless steel brushed tubing for maximum performance, corrosion resistance and strength eliminating cracking. aFe Twisted Steel Headers are engineered and manufactured in our Corona, California manufacturing facility. Twisted Steel 304 Stainless Steel Race Series Performance Package Nissan Patrol (Y61) 01-16 I6-4.8L Nissan Patrol (Y61) 01-16 I6-4.8L