AFR Heads, 3708 AFR BBC 18 Degree, CNC Ported (1 Head)

AFR’s new 457cc 18° Big Block Chevy heads 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 degree resulting in unparelled under the curve flow numbers..... don’t be fooled by just peak flow numbers. The combustion chamber come 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.

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.

11/32" Bead Lock Stainless Steel Exhaust Valve, 1.800" X 5.935" O.A.L.

PAC Racing #1258 1.645” OD Solid Roller Triple Spring, 350 lbs. on seat, .950” maximum lift Max RPM 8300 to 8500

10° Titanium Retainer 1.500" O.D X 1.180"I.D X .765" I.D

10° 11/32" Bead Lock Valve Keepers with recess lash caps

11/32" Viton Valve Seals

Hardened Spring Cup 1.740 O.D X 1.677 I.D X .570

Intake Valve Seats 2.500" O.D X 2.000" I.D X .375" Deep

Exhaust Valve Seats 1.900" O.D X 1.400" I.D X .375" Deep

11/32" Bronze Valve Guides .502" O.D X 2.700 O.A.L.

11/32" Exhaust Bronze Valve Guides .502" O.D x 2.25" O.A.L