Trick Flow® GenX® 255 HD Cylinder Heads for GM LS3

Trick Flow® GenX® 255 HD cylinder heads offer an unbeatable combination of performance and durability, making them the perfect upgrade for your high-performance GM LS3 engine build. Assembled with Manley Severe Duty stainless steel valves, these heavy-duty versions of the standard GenX® 255 heads can withstand the added heat, stress, and abuse dealt by big power adders. That makes them the ideal choice for engines using superchargers, turbochargers, or nitrous.

GenX 255 HD cylinder heads have fully CNC-profiled combustion chambers and CNC Competition Ported square port runners with a premium high resolution surface finish that guarantees dimensional accuracy and balanced flow from port-to-port for maximum power potential. The valve angles have been modified from the stock 15° to 12° to increase piston-to-valve clearance and allow the use of larger camshafts. The coolant holes through the head decks were designed to ensure compatibility with all LS head gasket and engine block combinations. The 6-bolt-per-cylinder mounting pattern for GMPP LSX and other aftermarket blocks increases clamping force to prevent head gasket failure, cylinder distortion, and other issues that plague the factory 4-bolt design.

Trick Flow® GenX® 255 HD heads have LS3 port locations to work with all LS3-style intake manifolds and LS9/LSA blower assemblies. They must be used on engines with 4.000" or larger bores.

Cylinder heads are available fully assembled or as bare castings. Sold individually. Show Less