1 7/8" Primaries, 3" Merge Collectors, 3" X-Pipe (No Cats)Ford claims 412 HP. We say it’s considerably more! The new 5.0L Coyote Mustang is here and quicker than you can blink, ARH has a header system. 100% U.S. made using the finest 304 S/S, the system fits great, installs relatively easy and produces HP gains normally seen in much bigger V8’s.Through stock mufflers and mid pipes (and no tuning) power was up 32 RWHP. We were blown away and so will you!Additional features include: 3/8” thick flanges, merge collectors with scavenger spikes, 200 cell metallic substrate cats, a direct fit X or H pipe and your choice of 1-3/4” or 1-7/8” primaries.Allow 1-2 Weeks for Fabrication.