JBA's Tri-Y long tube headers for 390/428 give you the power you're looking for in a package that fits like no other. JBA's designs are application specific to best fit the engine/transmission combination in your Mustang. They also feature big 1-3/4" primaries that flow in to 2-1/4" secondary tubes and terminate in a big 3" collector. Plus they are designed to give maximum ground clearance for street or track use. With heavy-duty stainless steel tubing, thick 3/8" laser-cut flanges and JBA sealing dome collector, you don't have to worry about leaks caused by lesser materials.