Afr 457cc Bbc 18° Magnum Aluminum Cylinder Head, Fully Cnc Ported

AFR’s new 457cc 18° Big Block Chevy head are our best performing highest flowing head in our BB Chevy lineup. They come standard with stainless steel 2.400 intake valves and 1.800 exhaust valves. The intake port is raised .500 with the valves rolled to 18° resulting in unparalleled under the curve flow numbers..... don’t be fooled by just peak flow numbers. The combustion chamber comes in at 90cc. This head is ideal for 540CI or larger race engines. This head requires specific pistons, valves covers, shaft mount rockers and readily available intake manifolds. AFR offers a wide range of options and upgrades for this head like titanium valves and Copper seats. AFR heads are available bare (without parts), call our tech line for details. Sold as a single piece, 2 pieces required per engine.
AFR Magnum 18 Degree 457 cc Big Block Chevy head are the highest flowing head offering from AFR for Big Block Chevy engines. By having the intake ports raised .500 in. along with the combination of moving the valves to 18 degrees, Magnum 18 degree cylinder head will flow a whopping 498 cfm of air through the intake ports at 1.000 in. lift. Designed for 540 ci and larger racing engines, AFR offers Magnum 18 degree fully assembled, bare CNC ported, and bare unported casting for custom port work.


Basic Package Components Part # 100% CNC Ported Intake Ports, Exhaust Ports, & Combustion Chamber
Competition 5-angle Valve Job   11/32" Bead Lock Stainless Steel Intake Valve, 2.400" X 6.035" O.A.L. AFR #7420 11/32" Bead Lock Stainless Steel Exhaust Valve, 1.800" X 5.935" O.A.L. AFR #7422 PAC Racing #1258 1.645” OD Solid Roller Triple Spring, 350 lbs. on seat, .950” maximum lift Max RPM 8300 to 8500 AFR #8014 10° Titanium Retainer 1.500" O.D X1.180"I.D X .765" I.D AFR #8517 10° 11/32" Bead Lock Valve Keepers with recess lashcaps AFR #9010 11/32" Viton Valve Seals AFR #6613 Hardened Spring Cup 1.740 O.D X 1.677 I.D X .570 AFR #9170 Intake Valve Seats 2.500" O.D X 2.000" I.D X .375" Deep AFR #9162 Exhaust Valve Seats 1.900" O.D X 1.400" I.D X .375" Deep AFR #9066 11/32" Bronze Valve Guides .502" O.D X 2.700 O.A.L. AFR #9055 11/32" Exhaust Bronze Valve Guides .502" O.D x 2.25" O.A.L AFR #9042   Recommended Components: Intake Port Gasket AFR #6880 Important: Do not port match your intake manifold to Fel-Pro gasket as it does not precisely fit AFR heads. Exhaust Port Gasket AFR #6858 Head Gasket, Fel Pro #1057 Fel Pro #1057 Head Gasket, Cometic C5434 Cometic C5434 Head Studs, ARP 135-4305 AFR #6345 1.8 Shaft Mount Rocker Arms T&D   1.8 Shaft Mount Rocker Arms Crower   1.8 Shaft Mount Rocker Arms Jesel   Suggested Manifold 10.2” Block AFR #4901 Suggested Manifold 9.8” Block AFR #4902 Spark Plug Starting Range Autolite 3932 Distributor Standard Deck MSD #84697 or #8489 Distributor Tall Deck MSD #85561 or #854   Recommended Components: Intake Port Gasket AFR #6880 Important: Do not port match your intake manifold to Fel-Pro gasket as it does not precisely fit AFR heads. Exhaust Port Gasket AFR #6858 Head Gasket, Fel Pro #1057 Fel Pro #1057 Head Gasket, Cometic C5434 Cometic C5434 Head Studs, ARP 135-4305 AFR #6345 1.8 Shaft Mount Rocker Arms T&D   1.8 Shaft Mount Rocker Arms Crower   1.8 Shaft Mount Rocker Arms Jesel   Suggested Manifold 10.2” Block AFR #4901 Suggested Manifold 9.8” Block AFR #4902 Spark Plug Starting Range Autolite 3932 Distributor Standard Deck MSD #84697 or #8489 Distributor Tall Deck MSD #85561 or #854

Installation Manual