AFR 210cc LSX Bare Cylinder Heads, 66cc Chambers, No Parts

The Small Port, High Velocity Torque Monster! - Information below is referring to fully assembled heads.
Designed specifically for 3.900 Bore LSX engines.
For the ultimate high performance street LS1/LS2/LS6 aluminum cylinder head AFR’s all new 210cc emission legal heads (E/O # D250-4) are your only choice. Specifically designed for 1997 to present Gen-3 Chevy Corvettes, Camaros, and trucks using a 3.900 Bore. AFR’s LSX cylinder head offers unmatched flow performance (302 CFM at .600lift) and features 2.020" intake and 1.600" exhaust valves with AFR’s iron ductile interlocking valve seats. With only 210cc port volume (nearly identical to a stock LS1 head) this is an incredible 70 CFM increase over stock casting, creating unbelievable port velocity and performance. The 210cc cylinder head is ideal for naturally aspirated 346 CI to 396 CI engines. It comes standard with 66cc combustion chambers. AFR’s LSX is a direct bolt on, no special parts required. 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 unparalleled durability. An exclusive new modern combustion chamber design with double quench pad area helps the LSX generate huge low and mid lift airflow numbers. If you need a snake charmer for that pesky neighborhood “Cobra Mustang” look no further!

Note: Hydraulic roller cams in "LS" Gen III engines typically experience valve float at 6600-6800 RPM's. If you are using aftermarket rocker arms valve float will become prominent and AFR highly recommends upgrading to the AFR part #8019 spring. If you plan on running over .600 gross valve lift and/or 6600 RPM, AFR suggests you upgrade your springs to AFR part #8019. The upgraded springs have higher seat and open pressures (155/410+) to better reduce the risk of valve float in more aggressive applications.
Note: LSX bead locks and aftermarket bead locks are not interchangeable. GM made their bead lock radius and depth different. AFR locks are the same as GM LSX.

Important: Do not port match you intake manifold to any Fel-Pro gasket as it does not precisely match AFR heads.
Note: Milling head deck will affect flow numbers.