When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
............It is probably lean due to that huge crack in the exhaust manifold. Would you concur?
My thoughts. Headers ... if tuned right ... scavenge exhaust from other cylinders using the pull of the flowing exhaust of other cylinders sharing that header, a vacuum of sorts can be created in the header. Exhaust being vacuumed out is easier than pushing it out, and vacates the cylinder faster for a better intake stroke filling it. Unless a really trick set of manifolds, I've never seen a cast iron manifold that preforms near like a tuned header ...rather most just serve to get used exhaust moved into a pipe to a muffler, etc. There are exceptions, but these trucks didn't get those "cast iron headers" A cracked manifold might leak and allow a slight drop in back pressure for that one cylinder, but not enough to lean it out like a cracked header can do as a header looses efficiency then. A cracked exhaust manifold will tick loudly, stink like hell, even let air into the exhaust leading to exhaust pops as unburned fuel in hot exhaust suddenly has oxygen maybe.
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
