Add more power to you 2011 - 2014 F150 Coyote with V8 - 5.0L engine by installing our new Race Only Twisted Steel headers. These headers feature a 1 - 58 mandrel - bent tuned length primary tubes that will out - flow the stock cast manifolds by 46. These headers are built using 409 stainless and thick 38 flanges for a leak - free seal. We designed the headers to incorporate a merge collector (header collector). A merge collector combines high flow and velocity to increase and broaden the engines torque curve, while reducing turbulences that are found in traditional form collectors. When combined with our off - road or catted y - pipes performance gains are increased as much as 10HP and 20 lbs. x ft of torque over the stock manifolds and factory y - pipe.