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AFR Cylinder Heads
AFR Big Block Chevy 300cc Oval Port Cylinder Heads
Full CNC BBC Performance 427-540 cuin Street/Strip Cylinder Heads

with current pricing

fully CNC ported 300cc high velocity oval port provides plenty cfm airflow and airspeed for endless HP and torque for street/strip performance or circle track applications

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afr cylinder head

*--click here to see cylinder head listings--
*--2.300/1.880 one piece stainless valves with 10° locks and hardened spring seats are standard--
*--113cc combustion chamber volumes--
*--choice of 1.550 hydraulic roller spring package or 1.550 mechanical roller spring package--
*--exhaust ports and bolt pattern are raised .375 (3/8”) over stock location, this rearly affects header or chassis fitment--
*--complete 100% CNC'd--Combustion Chambers, Exhaust Ports & Intake Ports---
*--see basic parts list and some suggestions on manifolds and gaskets--
*--A 3/4” thick head deck makes the AFR head ideal for nitrous or blower applications--great tech help @

If you need assistance in selecting the best AFR cylinder head for your application, you may want to e-mail a description of your combination or call 856-767-4095 or 856-767-7740, and we'll see if we can help out.

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FREE ground SHIPPING inside the continental USA on purchases over $2900.00--allow about 2-3 weeks for Cylinder Head orders to ship--
check out BBC Cylinder Head Options to add a few items you may need--

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BBC 300cc Oval Port go to
Flow Charts
go to
BBC Head Options
afr bbc cylinder headAFR BBC 300cc Oval Port Cylinder Head
AFR’s Fully CNC'D 300cc Big BLock Chevy head is perfect for 427-540cuin street/strip applications as well as circle trackcars that require strong low end and mid range torque to move the weight of the vehicle and produce enough airflow to feed those cu in's to the upper rpm band--always check for piston to chamber interference w/o a head gasket before final assembly (the chamber shape is very critical to flow and shouldn't be altered so contact material should be removed from the dome,if necessary)--
--   see basic parts list for parts included in head assembly and some suggestions on manifolds and gaskets--- --
Important: Hyd. roller springs will have 170/473lbs spring pressure & Mechanical roller spring will have 275/800lbs spring pressure
cc int shape part # valve/dia. runner
spring retainer seat pressure open pressure max. lift price/pair buy
oval 3660 2.300/1.880 300 Bare heads have full cnc port w/comp valve job $2753.83
3670 2.300/1.880 300 1.550 steel 170 473lbs .650 $3046.77
3680 2.300/1.880 300 1.625 steel 275 800lbs .850 $3151.53
go to
BBC 290cc Oval Port
Flow Charts go to
265cc Head Options
AFR 300cc BBC Fully CNC'd Oval Port Cylinder Head-Flow Chart cfm @28" H2O
valve size .200 .300 .400 .500 .550 .600 .650 .700
2.300 int. 165 240 296 338 358 376 385 388
1.880 exh. 135 185 234 266 274 282 290 297
go to
BBC 300cc Oval Port
go to
Flow Charts
BBC Head Options Top
the AFR BBC Cylinder Head Options listed below
may only be ordered along with a complete set of AFR Cylinder Heads--
--keep in mind, free shipping for purchases totaling $2900.00 or more for USA zipcodes--
Item description price buy
titanium retainer --FOR THE 1.550 SPRING ONLY--AFR Upgrade #8508-Titanium 10° Retainers installed in place of the steel retainers that are normally supplied $190.12
titanium retainer --FOR THE 1.625 SPRING ONLY--AFR Upgrade #8509-Titanium 10° Retainers installed in place of the steel retainers that are normally supplied $190.12
valve spring --AFR Upgrade #8039-upgrade trades the mechanical roller spring #8031 to a heavier mechanical spring Manley Nextek #8022-320lbs seat pressure-860lbs open pressure (@ .840 lift) with a max lift of .840 $124.16
comp cams ultra pro magnum rocker --Comp Cams ULTRA Pro Magnum Roller Rocker-1.7 ratio-"Lifetime Guarantee" so strong that the body is guaranteed for life against breakage and unlike alum. rockers, rockers can be rebuilt by replacing the trunion, roller tip, and bearings thru Comp Cams- $318.32

the AFR BBC Cylinder Head Basic Package Components are listed below
and a few specifications and suggestions for Supporting Components--
parts incl. w/Heads part # some suggestions
Intake Valve 2.300x5.500 Oal #7626 Cyl Head torque w/moly----75lbs
Exhaust Valve 1.880x5.448 Oal #7630 Rocker Stud Torque--------55lbs
Mech Roller Valve Spring 1.625-275/800lbs AFR #8031 Int Gasket----------GM 12366985
or Hyd roller Spring 1.550-170/473lbs AFR #8002 Exh Gasket----------AFR#6858
Manley 10° Chrome Moly Retainer1.550/valve locks AFR#8511/AFR#9005 Head Bolts Mark V----ARP#135-3707 or AFR#6308
Manley 10° Chrome Moly Retainer1.625/valve locks AFR#8518/AFR#9005 Head Stud kit-Mark V----ARP#235-4713 or AFR#6307
Viton Valve Seals #6611 Head Bolts Mark IV----ARP#135-3703 or AFR#6306
Hardened Spring Cup1.550/1.625 #8048/#8046 Manifolds------Edel Vic Jr, RPM Performer
Intake Valve Seats #9065 Spark Plugs-----Auto 3935
Exhaust Valve Seats #9064 Stud Girdle----------AFR#6210
Bronze Valve Guides-Intake #9045 spring pocket can be cut to 1.750, but no deeper
Bronze Valve Guides-Exhaust #9046
Intake Rocker Stud-7/16 #6407
Exhaust Rocker Stud-7/16 #6406
Adjustable Guide Plates-3/8 #6109