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