Products

AFR 227cc LT4 SBC Racing Cylinder Head

The Baddest 23°Standard Port Head

AFR 227 SBC LT Cylinder HeadHigh flowing AFR 227cc intake port small block Chevy 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 version features 100% CNC ported intakes with greater detail. Both come with 100% CNC ported 55cc or 65cc combustion chambers and 80cc exhaust ports with a 3/4” thick cylinder head deck (ideal for nitrous or blower applications). In addition we also offer 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 23º valve angle make this the perfect cylinder 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 cylinder heads are available in either standard or spread port exhaust. AFR offset stud girdles are the only special parts required (see footnotes here). 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 shaft mount rocker is used. The exhaust port is raised .250 over GM L-98 cylinder head.

Note:

These cylinder heads are specifically design for 1992-95 Corvettes and 1993-97 Camaros LT-1 and LT-4 engines using the GM LT-4 or equivalent manifold.

227cc SBC Aluminum Cylinder Head Street Flow Chart

227cc SBC Street Cylinder Head Flow Chart

 

227cc SBC Aluminum Cylinder Head Comp. Flow Chart

227cc SBC Competition Cylinder Head Flow Chart

 

 


227cc SBC Racing Aluminum Cylinder Head Part Numbers

CNC Ported Pairs of Heads Complete With Parts or Ready to Install

 Race Ready CNC Strip Ported Heads

 Description

 Part Number

 227cc Racing Head, LT4, Standard/Reverse Cooled, 55-65cc 1076

 Competition Package CNC Ported Heads

 Description

 Part Number

 227cc Racing Head, LT4, Standard/Reverse Cooled, 55-65cc 1126

Stage 1 Bare Heads (no parts or porting)

 Description

 Part Number

 227cc Racing Head, LT4, Standard/Reverse Cooled 1196

Not legal for sale or use on pollution controlled motor vehicles in the United States.


Basic Package Components Part #
100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
3-angle Valve Job
Intake Valve, 2.100" x .100" long AFR #7256
Exhaust Valve, 1.600" x .100" long AFR #7254
1.550" OD Roller dual valve spring w/ dampener,
225lbs on seat, .710" maximum lift (upgrades available)
AFR #8000
10° 4140 Chrome Moly Retainers AFR #8511
10° Valve Locks AFR#9009
7/16" Rocker Studs AFR #6405
5/16" Guide Plates AFR#6105
Valve Seals AFR #6612
Hardened Shims AFR #8045
Intake Valve Seats AFR #9060
Exhaust Valve Seats AFR#9070
Bronze Valve Guides

AFR#9051

Special orders available on request.

Specifications, Features, and Optional Supporting Components
Head Torque 65-70 ft. lbs
Rocker Stud Torque 55-60 ft. lbs
Intake Port Gasket, 1.310" X 2.180" w/ 3/8" radius AFR #6860
Exhaust Port Gasket Fel-Pro #1405, AFR #6835
Head Gasket 350cid Fel-Pro #1074, AFR #6803
Head Bolts & Studs Standard ARP, AFR #6310 & #6305
Head Bolt Washers Manley, AFR #6320
Stud Girdle AFR offset AFR #6208
Suggested Manifold

Victor Jr, Super Victor or HV1000
AFR #5005, #5003, or #5033

Spark Plug Starting Range

Autolite 3910

Combustion Chambers 55cc - 65cc
Spring Pocket can be cut to 1.750, no deeper  
Valve Spacing 60/40
Rocker Arms Standard
Valve Angle 23°
Angle Mill (milling options available) .008" per cc
Flat Mill (milling options available) .006" per cc
Pushrods 5/16" Hardened AFR #6601 - #6604


Important: Do not port match you intake manifold to Fel-Pro gasket as it does not precisely fit AFR heads.

Note: Milling head deck will affect flow numbers.



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