Bolt-on horsepower and torque with these short-tube headers. These headers are designed to fit 66-77 Broncos with 289/302 motors with ample clearance for most modified suspensions. Engineered to make strong power and torque throughout the RPM range with smooth mandrel-bent 1-1/2" primaries and 2.5" collectors. Extra thick 3/8" laser-cut flanges to guard against warping and heavy-wall 16 gauge tubing for maximum durability. Made from 304 Stainless Steel ensures these will last for many years to come. This header system includes high-quality hardware, premium laminated metal core gaskets, heavy-duty ball, and socket flanges for a leak-proof installation. Also includes "O2 Ports in Collectors for EFI conversion.