aFe Ford F-150 15-22 V8-5.0L Twisted Steel 304 Stainless Steel Headers - 48-33025-1 This system produced gains of up to +20 HP and +23 lbs. x Ft. TQ., as measured on our in-house dyno. This system is constructed of 1-5/8 IN mandrel-bent 304 stainless steel tubing for maximum strength and durability. Factory style laser cut machined mild... $785.00 Compare