LS3 12-Degree CNC Ported Cylinder Heads

The Air Flow Research LS3 12-Degr Cylinder Heads (AFR1845) are engineered for serious performance enthusiasts looking to extract maximum potential from their LS3 engines. These fully CNC-ported cylinder heads feature 260cc intake runners and 69cc combustion chambers, optimized for superior airflow and combustion efficiency. Designed for 4.000" or larger bore applications up to 454 CI, they support engine operation up to 7000 RPM. Key features include 2.165" intake valves, 1.600" exhaust valves, PAC Racing dual valve springs rated for .650" lift (up to 7000-7200 RPM), 7° titanium retainers, and billet valve seats. The 12° valve angle and 3/4" thick head deck provide durability and performance. These heads are designed as a direct fit for GM LS-Series engines and are compatible with the "Mongoose" LS3 application. They are suitable for both naturally aspirated peak power and forced induction reliability. The product is street legal in 50 states for 2007-2016 emission-controlled vehicles with a General Motors 6.2L LS engine. Installation may require specific components such as a FAST 92mm or 102mm manifold, specific head gaskets (Cometic 4.160" Bore Size recommended), and potentially longer pushrods. ARP head bolts (134-3610) and head studs (ARP #234-4317 for 2004+ blocks, ARP #234-4316 for pre-2004 blocks) are also recommended.