As incredibly efficient as the GM LS3 heads are straight from the factory, there’s always room for improvement, and that’s why companies like Trick Flow Specialties continue to develop ported, high-flow castings for the performance enthusiast. They’ve just launched these new GenX 255 heads for the LS3, and we have all of the details for you below.
Trick Flow Specialties GenX 255 Cylinder Head For LS3
Yes, it’s true–Trick Flow’s GenX 255 square port cylinder heads for GM LS3 engines are now available.
Trick Flow engineers combined the best features of GM’s LS3 and LS7 cylinder heads with its own race-winning engineering and technology to create the ultimate square port LS cylinder head.
The GenX 255s feature fully CNC Competition Ported square port runners with a premium, high resolution surface finish for maximum airflow and performance potential. The valve angles have been changed from 15° to 12° to increase piston-to-valve clearance and allow the use of larger camshafts. Trick Flow even includes new rocker rail mounts to accommodate stock-style LS3 1.7 ratio rocker arms.
The GenX 255 cylinder heads are available fully assembled with valves, valve springs, locks, retainers, and guideplates with a choice of steel or titanium retainers. The heads are also available with a choice of standard- or six-bolt mounting patterns.
Specifications • Intake Runners: 255cc CNC Competition Ported • Exhaust Runners: 87cc CNC Competition Ported • Combustion Chambers: 69cc CNC-profiled • Valves: 2.165 inch intake/1.600 inch exhaust, one-piece stainless steel • Valve Springs: Trick Flow Track Max Pacaloy 1.300 O.D. dual, .650 inch maximum valve lift
Applications The GenX 255 cylinder heads fit GM LS3 and other LS engines with 4.000″ and larger cylinder bores. The coolant holes through the head deck are redesigned to work with all LS head gasket and engine block combinations. OEM-type LS3 ports accommodate LS3-style intake manifolds and LS9/LSA blower assemblies. Heads with six-bolt mounting pattern not compatible with 2010-up Camaro exhaust manifolds—aftermarket headers required.