AFR’s MONGOOSE LS3 Rectangle Port cylinder heads are 100% 5-AXIS CNC ported and made with A356 aluminum. All heads come with high quality components, such as titanium retainers and Pac Racing Springs. Available in runner a 260cc runner volume these heads are CARB Certified EO #D-250-5. Component upgrades and different machining options are available to customize your AFR heads for your specific build. Minimum bore sizing is 4.000” to accommodate intake valve clearance.