AFR 227cc LT4 Competition Eliminator SBC Aluminum Cylinder Heads

The Most Powerful LT4 AFR Racing Head!
High flowing AFR LT4 227cc intake port angle plug aluminum cylinder heads are available in two 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 and higher flowing exhaust ports. Both come with 100% CNC ported 55cc-65cc combustion chambers and 80cc exhaust ports with a 3/4" thick head deck (ideal for nitrous or blower applications). 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 only in standard 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. Dual valve cover bolt pattern is standard.
The exhaust ports are raised .250" over a standard GM L-98 cylinder head.

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" O.A.L.	AFR #7256
8mm Bead Lock Exhaust Valve 1.600" x 5.030" O.A.L.	AFR #7254
1.550" OD Roller Dual Valve Spring w/ dampener, 220 lbs on seat, .710" maximum lift	AFR #8000
Manley 10° Steel Retainers 1.500" O.D x 1.120" I.D x .705" I.D	AFR #8505
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 .600" O.D x .495" I.D	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" O.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
8 mm Bronze Valve Guides .502" O.D x 2.100" O.A.L	AFR #9051

Specifications, Features, and Optional Supporting Components

Material	A356 Aluminum
Intake Port Volume	227cc
Intake Port Dimension	2.240" H x 1.310" W 3/8 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	55cc or 65cc
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.
Spark Plug Dimensions	14mm x .750" w/Gasket Seat
Carb EO#	Not Emissions Complient
Intake Port Gasket	AFR #6860
Exhaust Port Gasket, Fel-Pro #1405	AFR #6835
Head Gasket, 350cid Fel-Pro #1074	AFR #6803
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 GM L98	AFR #6200
Suggested Manifold	GM LT4 or Edelbrock LT4
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. Angle mills might require .120" Thick intake gasket.