Afr 227cc Competition Eliminator Sbc Cylinder Heads, Spread Port, 65cc Chambers

Spread port heads have the center exhaust ports spread apart approximately 1/2" over stock GM heads. The reason for spread port heads is to achieve additional cooling in the center of the head where the heat concentration is greatest. As standard headers do not fit, spread port headers are required since the center ports are spread further apart than stock GM products. The increased spacing on the exhaust port also requires the use of exhaust gasket Fel-Pro #1409. Spread port heads only come with a Stahl bolt pattern. AFR's spread port head has all the benefits and features of AFR's standard head. As all benefits and features are the same, please review respective page for product details (i.e. for 210cc spread port view 210cc SBC "Eliminator").
Timeless Design - The original AFR 60/40 Valve Spacing Head!
High flowing AFR 227cc intake port small block Chevy angle plug aluminum cylinder heads are available in three stages of performance. The Race Ready version features 100% CNC ported intakes while the higher flowing Competition Package features 100% CNC ported intakes with greater detail. Both come with 100% CNC ported 65cc or 75cc combustion chambers and 80cc exhaust ports with a 3/4" thick head deck (ideal for nitrous or blower applications). In addition AFR also offers the "as cast" Stage 1 heads for 227cc performance on a budget. Standard valves are lightweight 8mm 2.100" intake and 1.600" exhaust with AFR's hardened ductile iron interlocking valve seats. The 227 has 60/40 valve spacing and piston valve pockets should be checked. The exceptional flow characteristics and 23 degree valve angle make this the perfect head for 350 to 434 cid engines in drag cars, sprint cars, and late model oval trackers operating from 4500 rpm and up. The 227cc aluminum cylinder heads are available in either standard or spread port exhaust. AFR offset stud girdles are the only special parts required. Some applications require shaft mount rockers or .050 offset rocker arms for durability and reliability of valve train components. Standard rockers can be used but the intake rocker arm will be at a slight angle and the roller tip will not be perfectly centered on the valve tip. Not recommended for street use, unless a shaft mount rocker system is used. Drilling for centerbolt valve covers available as an option. The exhaust ports are raised .250" over a standard GM L-98 cylinder head.

Note:
2.100 valves will require aftermarket pistons notched for valve clearance.

Basic Package Components Part # 100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
Competition 5-angle Valve Job
8mm Bead Lock Intake Valve, 2.100" x 5.000" Overall Valve Length AFR #7256 8mm Bead Lock Exhaust Valve, 1.600" x 5.030" Overall Valve Length AFR #7254 PAC Racing Spring 1.550" OD Solid Roller Dual Valve Spring, 220 lbs on seat, .710" maximum lift, Max RPM 7200-7400 AFR #8000 Manley 10? Steel Retainers 1.500" O.D x 1.120" I.D x .705" I.D AFR #8511 10? Bead Lock Valve Keepers with lashcap recess AFR #9009 ARP 7/16" Rocker Studs AFR #6405 Adjustable 5/16" Guide Plates AFR #6103 Viton Valve Seals AFR #6612 Hardened Valve Spring I.D Locator 1.550" O.D x .780" I.D AFR #8048 Ductile Iron Intake Valve Seats 2.200" O.D x 1.750" I.D x .375" Deep AFR #9060 Ductile Iron Exhaust Valve Seats 1.696" O.D x 1.325" I.D x .305" Deep AFR #9070 Bronze Valve Guides AFR #9051
Specifications, Features, and Optional Supporting Components Head Material A356 Aluminum Intake Port Volume 227cc Intake Port Dimension 2.200" H x 1.290" W 5/16 Radius Intake Port Location Stock Exhaust Port Volume 80cc Exhaust Port Dimension 1.430" H x 1.540" W Exhaust Port Location .250" Raised Combustion Chamber Size 65cc or 75cc Valve Cover Bolt Pattern Perimeter Bolt Valve Angle 23? Valve Spring Pocket Diameter 1.580" O.D Max Valve Spring Pocket Machining 1.680" O.D Deck Thickness .750" Minimum Bore Diameter 4.000" Flat Mill .006" per cc 60cc Maximum Angle Mill .009" per cc 55cc Maximum Minimum Cross Sectional Area 2.340 sq. in. Note:Angle mills might require a .120" Thick intake gasket. Spark Plug Dimensions 14mm x .750" w/Gasket Seat Carb EO# Non Emissions Compliant Shaft Mount Rocker Arms, T&D .450" off-set AFR #6055
Stud Mount Rocker Arms, Hardland Sharp .050 offset AFR #6036 Stud Mount Rocker Arms, Hardland Sharp .050 offset AFR #6035 Intake Gasket 1.280x2.090 w/ 3/8" radius, Fel-Pro #1206 AFR #6820 Exhaust Port Gasket, Fel-Pro #1409 Fel-Pro #1409 Head Gasket, 350cid Fel-Pro #1003 AFR #6800 Head Gasket, 400cid Fel-Pro #1014 AFR #6802 SB Chevy Head Bolt Kit, ARP #134-3701 AFR #6310 SB Chevy Head Stud Kit, 12 Point Nuts, ARP #234-4301 AFR #6305 Head Bolt Washers, Manley AFR #6320 Stud Girdle AFR Offset AFR #6208 Suggested Manifold AFR Titan TXR #4801
Suggested Manifold AFR  Titan TXS #4802
Spark Plug Starting Range Autolite 3922 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.