Afr 315cc Bbc Magnum Rectangle Port Cylinder Heads, Cnc Ported

AFR's 315cc heads feature 100% CNC ported intake, exhaust & chambers, A356 aluminum castings and high quality components throughout. Recommended for aggressive street, or street/strip builds with displacements up to 540 cubic inches, operating up to 6800 RPM. Component upgrades and machining options are available to customize AFR Heads to your specific build.
AFR's Torque Monster!
The smallest intake volume runners in AFR's BBC rectangle port line-up, but don't let size fool you. AFR's fully CNC ported 315cc aluminum cylinder heads will provide you with flow numbers most medium sized heads, and some larger, can only dream about. This line was designed to optimize low and mid-lift airflow, while still generating impressive peak figures. Their application should be focused on smaller cubic inch Big Blocks (396-502), with a primary operating range of 2500-6800 rpm’s (this range is an average and will vary with engine displacement as well as component selection). These heads should also be given strong consideration in larger street driven or marine applications up to 555 CID, where low rpm power and drivability are a factor. The 315 version is extremely versatile with its incredibly strong low and midlift airflow figures as well as peak numbers approaching the 400 CFM mark. These heads would be a great choice if your looking for big torque, strong low rpm performance, and still have good rpm capabilities. The 315cc come standard with AFR's trademark .750" thick head deck, reinforced rocker stud bosses, and are equipped with premium one piece stainless steel 2.250" intake valves and 1.880" exhaust valves. Standard combustion chamber volume is 121cc for our BBC 315cc. Properly selecting the correct cylinder head for an application depends on a large number of variables. Please consult with one of our sales technicians to assist you in making the best decision for your particular application.

Note:
Optional stud girdle required for 2° rolled valve angles and 1" longer head bolts needed on four bottom exhaust bolt holes. Longer pushrods might also be required.

Basic Package Components Part # 100% CNC Ported Chambers, Exhaust and Intake
Competition 5-angle Valve Job
11/32" Intake Valve, 2.250" x 5.500" O.A.L AFR #7620 11/32" Nail Head Exhaust Valve, 1.880" x 5.450" Overall Valve Length AFR #7630 Manley 10° Steel Retainers 1.500" O.D x 1.168" I.D x .844" I.D AFR #8518
PAC Racing Spring #1224 1.625 O.D. Solid Roller, 275lbs on seat, .850 Maximum Lift, Max RPM 7400-7600 AFR #8031
10° 11/32" Valve Locks with lashcap recess AFR #9005 ARP 7/16" Rocker Exhaust Studs AFR #6406 ARP 7/16" Rocker Intake Studs AFR #6407 Adjustable 3/8" Guide Plates AFR #6109 11/32" Viton Valve Seals AFR #6611 Hardened Spring Cup 1.740" O.D / 1.650" I.D AFR #8046 Intake Valve Seats 2.450" O.D x 2.000" I.D x .375" Deep AFR #9062 Exhaust Valve Seats 2.000" O.D x 1.580" I.D x .375" Deep AFR #9064 11/32" Intake Bronze Valve Guides .531" O.D x 2.10" O.A.L AFR #9045 11/32" Exhaust Bronze Valve Guides .531" O.D x 2.25" O.A.L AFR #9046
Specifications, Features, and Optional Supporting Components Head Torque 75 ft. lbs Intake Port Gasket AFR #6853 (.120" Thick) or AFR #6855 (.060" Thick) Exhaust Port Gasket AFR #6858 Head Gasket, Fel-Pro #1047 (Mark V and VI) AFR #6849 Head Gasket, Fel-Pro #1017-1 (Mark IV) AFR #6350 Head Bolts, ARP 135-3703 (Mark IV) AFR #6306 Head Bolts, ARP 135-3707 (Mark V) AFR #6308
Head Studs, ARP 235-4713 AFR #6307 Head Bolt Washers, Manley AFR #6320 Suggested Manifold Super Victor Victor Jr.,  Spark Plug Starting Range Autolite 3932 Combustion Chambers 121cc w/ CNC Chambers or 117cc w/ As Cast Chambers Valve Spring Pocket Diameter 1.725 O.D
Intake Port Dimension 2.450"H x 1.755"W x 13/32 Radius Exhaust Port Dimension 1.780"H x 2.025" W Valve Angle 24°/4° Intake, 15°/4° Exhaust Angle Mill
.009" per cc/ Maximum 104cc as cast or CNC Chamber Flat Mill
.006" per cc/ Maximum 108cc as cast or 114cc CNC Chamber Stud Girdle, (AFR Specific) AFR #6202 Important: Do not port match you intake manifold to any Fel-Pro gasket as it does not precisely match AFR heads.
Note: Milling head deck will affect flow numbers. 1" longer head bolts needed on four bottom exhaust bolt holes. Angle mills might require a .120 thick intake gasket.