This system produced gains of up to +9 HP and +17 lbs. x Ft. TQ., as measured on our in-house dyno. This cat-back exhaust system is constructed of 3 IN - 2-1/2 IN mandrel-bent 409 stainless steel tubing for maximum strength and durability. This system features a high-flow 409 stainless steel muffler, producing a aggressive sound. Finishing off this exhaust system are dual 3-1/2 IN diameter black 304 stainless steel clamp-on exhaust tips. The tips features a laser etched aFe POWER logo for a unique style. This system produces an aggressive sound unleashing all available horsepower and torque. Utilizing a factory style flange and hangers this system is a direct bolt-on system, which requires no cutting or modifications for a hassle-free installation. Utilizing state-of-the-art computer-aided design technology, this exhaust system is designed for custom, high tolerance factory fitment. 100% MIG-Welded for race-proven strength and durability. Rebel Series 3 IN to 2-1/2 IN 409 Stainless Steel Cat-Back Exhaust w/Black Tip Ford F-150 21-24 V6-2.7L (tt)/3.5L (tt)/V8-5.0L Ford F-150 21-24 V6-2.7L (tt)/3.5L (tt)/V8-5.0L