Exhaust Manifold/Headers - 2018 Mustang

When scavenging Ford S550 Mustang exhaust manifolds in the junkyard, target 2015-2017 GT models equipped with the Gen 2 Coyote 5.0L. The OEM cast iron manifolds, part numbers FR3Z-9430-A (driver/left) and FR3Z-9431-A (passenger/right), are direct bolt-ons for 435hp engines. Visually inspect for hairline cracks at the four-tube collector junction and check flange surfaces for warping using a straightedge—these castings suffer thermal fatigue after 80k miles. Verify all eight manifold studs extract cleanly; seized hardware often requires drill-outs and Helicoil repairs. Installation demands new Ford multi-layer steel gaskets and strict torque sequence (typically 18 ft-lb in crisscross stages) to prevent leaks. Note that 2018+ Mustangs switched to the Gen 3 Coyote with revised exhaust port spacing; while externally similar, these manifolds do not align correctly with Gen 2 heads. If your 2018 build shows 435hp, verify engine code before purchasing. Look for casting marks like CF1E-9430-AA on the collector for authentication.