AFR 260cc LS3 Mongoose cylinder heads are 100 percent 5-axis, CNC-ported, and feature titanium retainers, A356 aluminum castings, and Pac Racing springs. These CARB certified heads require 4.000 in. or larger bore applications on up through 454 cu. in. engines operating at or below 7,000 rpm. They flow over 380 cfm at 0.700 in. lift and are designed primarily for street and strip applications. Structural features like Air Flow Research's trademark 3/4 in. thick head deck, reinforced rocker stud bosses, and thick wall runners provide unparalleled durability. They require the use of AFR stud girdles and full roller rocker arms. When it comes to building power, start with AFR 260cc LS3 Mongoose cylinder heads.