Afr 300cc Bbc Oval Port Cylinder Heads, Cnc Ported, Solid Roller Springs

AFR's 300cc heads feature 100% CNC ported intake, exhaust & chambers, A356 aluminum castings and high quality components throughout. Recommended for aggressive street, street/strip or race 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.
The Ultimate Street Weapon!
For the ultimate in "Oval Port" performance with solid roller springs, the fully CNC ported AFR 300 has no competition. With flow figures most small to medium sized rectangular port castings would be envious of, these high flowing "Ovals" produce tremendous airspeed and really pack a punch. AFR has included it's trademark 3/4" deck, reinforced rocker stud bosses, and thick rugged castings, so you can own the strongest and most efficient heads on the market today. Premium hardware all come as standard equipment. Take note the higher flowing exhaust ports are raised .375 over stock location, and therefore these heads might not be a direct bolt-on in every application. These heads have no EGR and are not emissions legal.

Note:
1" longer head bolts needed on four bottom exhaust bolt holes. Angle mills might require a .120" Thick intake gasket.

Basic Package ComponentsPart #100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
100% CNC Ported Combustion Chambers
Competition 5-angle Valve Job
11/32" Intake Valve, 2.300" x 5.500" O.A.LAFR #762611/32" Nail Head Exhaust Valve, 1.880" x 5.450" Overall Valve LengthAFR #7630PAC Racing Spring #1224 1.625 O.D. Solid Roller, 275lbs on seat, .850 Maximum Lift, Max RPM 7400-7600, Uses #8518 Steel Retainer (upgrades available)AFR #8031
10° 11/32" Valve Locks with lashcap recessAFR #9005ARP 7/16" Rocker Exhaust StudsAFR #6406ARP 7/16" Rocker Intake StudsAFR #6407Adjustable 3/8" Guide PlatesAFR #610911/32" Viton Valve SealsAFR #6611Spring I.D Locator 1.550" O.D x .780" I.DAFR #8048Intake Valve Seats 2.450" O.D x 1.950" I.D x .375" DeepAFR #9065Exhaust Valve Seats 2.000" O.D x 1.580" I.D x .375" DeepAFR #906411/32" Intake Bronze Valve Guides .531" O.D x 2.10" O.A.LAFR #904511/32" Exhaust Bronze Valve Guides .531" O.D x 2.25" O.A.LAFR #9046
Specifications, Features, and Optional Supporting ComponentsHead Torque75 ft. lbsIntake Port GasketMr. Gasket #107 or GM #12366985Exhaust Port GasketAFR #6858Head Gasket, Fel-Pro #1047 (Mark V and VI)AFR #6849Head Gasket, Fel-Pro #1017-1 (Mark IV)AFR #6350Head Bolts, ARP 135-3703 (Mark IV)AFR #6306Head Bolts, ARP 135-3707 (Mark V)AFR #6308
Head Studs, ARP 235-4713AFR #6307Head Bolt Washers, ManleyAFR #6320Suggested ManifoldRPM PerformerVictor Jr., Spark Plug Starting RangeAutolite 3932Combustion Chambers112cc with CNC ChambersValve Spring Pocket Diameter1.725 O.D
Intake Port Dimension2.055"H x 1.840"W x1/2 RadiusExhaust Port Dimension1.770"H x 2.010" WValve Angle24°/4° Intake, 15°/4° ExhaustAngle Mill (Milling options available) 97cc max
.009" per ccFlat Mill (Milling options available) 102cc max
.006" per ccStud Girdle, (AFR Specific)AFR #6202Important: 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.