AFR 225cc LS1 Mongoose Cylinder Head - The Ultimate Bolt-On Emission Legal Street/Strip Weapon - (PN:AFR1610) Fits most LS based engines. For the maximum high performing street/strip LS1/LS2/LS6 aluminum cylinder heads AFR’s all new 225cc emission legal E/O #D250-4 are hands down the best choice. Specifically designed for 1997 to present Gen-3 Chevy Corvettes, Camaros, and trucks. AFR’s LS1 cylinder head offers unmatched flow performance and features 2.080 intake and 1.600 exhaust valves with AFR’s iron ductile interlocking valve seats. Our 225cc cylinder head is ideal for normally aspirated 396C.I. to 427C.I. For a wild 346 ci the 225 is a good choice, however some low RPM loss of torque might occur. It is available with 62cc, 65cc, and 72cc combustion chambers. AFR’s LS1 is a direct bolt on, no special parts required (see footnotes here). Structural features like Air Flow Research’s trademark 3/4” thick head deck, a must for blown and nitrous applications, reinforced rocker stud bosses and thick wall runners provide unparalled durability. An exclusive new modern combination chamber design with double quench pad area helps the LS1 generate huge low and mid lift airflow numbers. If you need a snake charmer for that pesky neighborhood “Cobra Mustang” look no further!