3-4 week build time. AFRs 260cc LS3 Mongoose heads are the ultimate rectangular port for the LS3 and L99 engines. They feature 100% CNC ported intake, exhaust and chambers using our advanced engineering and flow techniques to produce the ultimate Rectangle Port head available today. Featuring A356 aluminum castings, titanium retainers and the highest quality components, throughout. Theyre designed for 4.000 or larger bore applications up to 454 CI, operating up to 7000 RPM. Emmisons legal for 2008 to 2015 vehicles under CARB #D-250-5. Component upgrade and machining options are available to customize AFR Heads to your specific build. The Ultimate Bolt-On Emission Legal Street/Strip Weapon! 260cc Aluminum LS1 Cylinder…