GenX 255 GM LS3 Cylinder Head

The Trick Flow GenX 255 cylinder head is engineered for performance enthusiasts seeking to maximize the potential of GM LS3 and LS7 engines. These heads boast fully CNC-machined runners with a high-resolution surface finish for enhanced airflow and performance, featuring a 255cc intake runner volume and 87cc exhaust runner volume. The combustion chamber is also CNC-machined to 69cc, with a heart-shaped combustion chamber style. For improved piston-to-valve clearance and compatibility with larger camshafts, the valve angles have been adjusted from 15° to 12°. Constructed from durable cast aluminum, these assembled cylinder heads come equipped with titanium retainers, dual valve springs rated for up to 0.625 in. of valve lift, and 7-degree locks. They include intake and exhaust valves with 2.165 in. and 1.600 in. diameters respectively, along with valve guides and seats. The heads are designed for 6-bolt LSX-based engines with a minimum bore diameter of 4.000 inches. They also include new rocker arm rail mounts specifically for use with LS3 1.7 ratio rocker arms, as OEM mounts will not work. These cylinder heads are not intended as stock replacements. They are compatible with Chevrolet vehicles from 2008-2017 equipped with the 6.2L/376 V8 LS engine family. It's important to note that these heads do not fit 2010 and later Chevrolet Camaro OEM exhaust manifolds, and aftermarket headers are required. The Trick Flow GenX 255 cylinder heads are emissions-legal in California under CARB E.O. #D-747 for 2007-present GM vehicles with 6.2L engines.