For the maximum street/strip LS1/LS6 aluminum cylinder head AFR’s all new 225cc emission legal head E/O #D250-4 are hands down the best choice. Specifically designed for 1995 to present Gen-3 Chevy Corvettes, Camaros, and trucks. AFR’s LS1 head offers unmatched flow performance and features 2.080 intake and 1.600 exhaust valves with AFR’s iron ductile interlocking valve seats. The 225cc 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 and 72cc combustion chambers. An affordable “as cast” version is also available. AFR’s LS1 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 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!

Note:
Hydraulic roller cams in "LS" Gen III engines typically experience valve float at 6600-6800 RPM's. If your plan on running over .600 gross valve lift and/or 6600 RPM, AFR suggest you upgrade your springs to AFR part #8019. Our upgrade spring has higher seat and open pressures (145/390+) to better reduce the risk of valve float in more aggressive applications. AFR also recomends the use of Comp "R" lifters in conjunction with our 8019 spring upgrade.
(Flow Charts at bottom of page)