AFR 305cc BBC Marine Rectangle Port Cylinder Heads, Partially Ported

AFR is proud to announce their new BBC Marine Cylinder Head! This AFR 305cc marine rectangle port heads feature partially inconel exhaust valves, hydraulic roller springs, hard coat anodizing and high quality components throughout. Recommended for moderate street, or street/strip builds with displacements up to 509 cubic inches, operating up to 6500 RPM. Also available with 100% CNC chambers for increased air flow (see chart). Component upgrades and machining options are available to customize AFR Heads to your specific build.

AFR has been manufacturing BBC Marine Cylinder Heads for over a decade with great success. Many of the top marine engine builders in the industry rely on AFR for the performance in their engines. Today we are pleased to announce that you too can receive the same great AFR performance with an easier way to order your AFR cylinder heads. These cylinder head assemblies will come complete with Inconel Exhaust Valves, Hydraulic Roller Springs, and Hard Coat Anodizing.

Basic Package Components	Part #
50% CNC Ported Exhaust Ports 20% CNC Ported Intake Ports 30% CNC Ported Combustion Chambers 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. Hydraulic Roller, 275lbs on seat, .725 Maximum Lift, Max RPM 6500	AFR #8061
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 VictorVictor 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	2.380"H x 1.680"W x 11/32 Radius
Exhaust Port Dimension	1.720"H x 1.920" 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.