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 3-angle Radiused Valve Job
Bead Lock Intake Valve, 2.100" x 100L	AFR #7256
Bead Lock Exhaust Valve, 1.600" x 100L	AFR #7254
1.550" OD Dual Solid Roller Valve Spring w/ dampener,	AFR #8000
225 lbs on seat, .710" maximum lift (upgrades available)	Pacaloy #8001
10° Chrome Moly Retainers	AFR #8511
10° Bead Lock Valve Keepers	AFR #9009
7/16" Rocker Studs	AFR #6405
Guide Plates	AFR #6105
Viton Valve Seals	AFR #6612
Hardened Spring Seat	AFR #8045
Intake Vavle Seats	AFR #9060
Exhaust Vavle Seats	AFR #9070
Bronze Valve Guides	AFR #9051

Specifications, Features, and Optional Supporting Components

Head Torque	65-70 ft. lbs
Rocker Stud Torque	55-60 ft. lbs
Intake Gasket	AFR #6860
Exhaust Port Gasket	Fel-Pro #1405, AFR #6835
Head Gasket 350 cid	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 AFR Offset AFR Only	AFR #6208
Suggested Manifold	GM LT4
Spark Plug Starting Range	Autolite 3910
Combustion Chambers	55cc-65cc
Spring Pocket	Can be cut to 1.680, no deeper
Valve Spacing	60 / 40
Rocker Arms	Shaft Mount Recommended
Valve Angle	23°
Angle Mill (Milling options available)	.008" per cc
Flat Mill (Milling options available)	.006" per cc

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.