AFR BBC Aluminum Heads 305cc Magnum Comp Assembled

AFR BBC magnum comp aluminum heads 305cc intake ports assembled with 2.250 Intake/ 1.880 Exhaust valves, 121cc CNC combustion chamber. Recommended for moderate street, or street/strip builds with displacements up to 509 cubic inches, operating up to 6500 RPM. Big Block Chevy Cylinder Head Magnum Comp  Assembled 2.250 / 1.880 in Valves 305 cc Intake 121 cc Chamber  1.625 in Springs Aluminum 24 Degree Valve Angle  Pair 305cc w/ 100% CNC Chamber Flow Chart   .200 .300 .400 .500 .600 .650 Int 154 225 280 316 345 362 Exh 133 187 223 249 259 264 Test conducted at 28" of water (pressure) on Superflow 600Bore Size: 4.310", 3/4" radius plate exhaust, 2 1/8" curved pipe