The AFR Emissions Legal (CARB EO #D-250-2 for engines up to 1994), 195cc intake port LT4 small block Chevy aluminum cylinder heads are available in an LT4 angle plug version. These heads feature a 55cc to 65cc combustion chamber with a 64cc exhaust port and a 3/4î thick head deck (ideal for nitrous or blower applications). Standard valves are 2.020 intake and 1.600 exhaust with AFRÍs hardened ductile iron interlocking valve seats. The exceptional flow characteristics, ideal operating range of 2500 rpm to 6500 rpm (higher rpm ranges possible depending on combination of parts), 23_ valve angle, and standard valve spacing make this the perfect street head for 350 cid to 383 cid engines. Designed specifically for 1996 Corvettes or LT4 manifold users. No special parts are required. Dual valve cover bolt pattern is standard. Exhaust port is raised .100 over GM L98 cylinder heads. Note: Hydraulic roller cams typically experience valve float at 6000-6200 rpm because of their fast ramp rates. AFR suggest you upgrade your springs to AFR part #8047, 1.530 O.D. with higher spring pressures and use our Patented ñHydra Rev Kitî to reduce chances of valve float associated with rpm 6000 or higher. Chevrolet LT4 - 195cc Stage 1 Bare Heads - 70cc Combustion Chambers, L98 Plug