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The 315cc heads are AFR's largest and best flowing BBF heads! They feature 100% CNC ported intake, exhaust & chambers, A356 aluminum castings, and high quality components throughout with .250 raised exhaust port locations. These heads are best suited for large displacement high RPM Big Block Ford racing engines or radical “Pro Street” style builds. Please note, due to AFR's valve angle and location, custom pistons or notching existing pistons will be required. AFR heads are available bare (without parts), call our tech line for details. Please see footnotes for additional information.

315cc Aluminum BBF Cylinder Heads
Part # Description Combustion Chamber
3834 Competition Porting, .250" Raised Exhaust
w/ Hydraulic Roller Springs
3835 Competition Porting, .250" Raised Exhaust
w/ Solid Roller Springs
3837 Competition Porting, .250" Raised Exhaust
w/ Hydraulic Roller Springs
3838 Competition Porting, .250" Raised Exhaust
w/ Solid Roller Springs

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315cc Street Head Flow Chart
  .200 .300 .400 .500 .600 .650 .700 .750
Int 162 244 305 355 394 405 414 419
Exh 124 166 212 248 267 272 276 276

Test conducted at 28" of water (pressure) on Superflow 600
Bore Size: 4.380", 3/4" radius plate exhaust, 2 1/8" curved pipe

Included Components
100% CNC Ported Combustion Chambers
100% CNC Ported Intake & Exhaust
Competition 5-Angle Valve Job
11/32" Bead Lock Intake Valve 2.300" x 5.250" O.A.L
11/32" Bead Lock Tulip Exhaust Valve 1.760" x 5.050" O.A.L
PAC Racing #1224 1.625" OD Solid Roller Dual Valve Spring 275 lbs. on seat, .850" maximum lift, Max RPM 7400-7600 Uses #8518 Steel Retainer & #8046 Spring Cup (upgrades available)
10° Manley Steel Retainers 1.500" O.D x 1.168" I.D x .844" I.D
PAC Racing #1940 1.550" OD Hydraulic Roller Dual Valve Spring 175 lbs. on seat, .725" maximum lift Max RPM 6500-6700; Uses #8511 Steel Retainer
10° Steel Retainers 1.500" O.D x 1.120" I.D x .705" I.D
10° 11/32" Beadlock Valve Keepers with lashcap recess
ARP 7/16" Rocker Studs
Adjustable 3/8" Guide Plates
11/32" Viton Valve Seals
Hardened Valve Spring I.D Locator 1.550" O.D x .705" I.D
Intake Valve Seats 2.450" O.D x 1.950" I.D x .375" Deep
Exhaust Valve Seat 1.900" O.D. x 1.400" I.D. x .375" Deep
11/32" Exhaust Bronze Valve Guides .502" O.D x 2.25" O.A.L
Specifications & Features:
A356 Aluminum
Intake Port Volume
Intake Port Dimension
2.275" H x 1.850" W x .575 Radius
Intake Port Location
Exhaust Port Volume
Exhaust Port Dimension
1.850"H x 1.600"W
Exhaust Port Location
.250" Raised
Combustion Chamber Size
75cc or 85cc
Valve Cover Bolt Pattern
Perimeter Bolt
Valve Angle
14° Intake/8° Exhaust
Valve Cant
4.04° Intake/4.12° Exhaust
Valve Spring Pocket Diameter
1.750" O.D
Max Valve Spring Pocket Machining
1.750" O.D
Deck Thickness
Minimum Bore Diameter
Minimum Cross Sectional Area
3.440 sq. in.
Spark Plug Dimensions
14mm x .750" w/Gasket Seat
CARB Status: This product is not legal for sale or use on emission-controlled vehicles and intended for dedicated race vehicles only.


  1. AFR Big Block Ford

    • Heads are designed for 3/8" pushrods. Larger pushrods will not fit without clearancing and is not recommended since some areas are very thin. AFR recommends the use of .120" thick-wall pushrods.
  2. General Recommendations for AFR Cylinder Heads:

    • Bar Codes - Please keep the bar code & paperwork shipped with your head, these contain all the specs for your heads when calling AFR.
    • High Volume/Pressure Oil Pumps - If you are using a high volume or high pressure oil pump it can submerge the valve seals in oil causing smoking or oil consumption. Your block manufacturer or engine builder can recommend oil restrictions to the top end/valve train components.
    • Pushrods - Different length pushrods might be required, always check pushrod length. Check pushrod clearance with heads placed on the block before final assembly. Larger pushrods will not fit without clearancing and is not recommended since some areas are very thin. AFR recommends the use of .120" thick-wall pushrods.
    • Mills - Flat or angle mills could affect flow numbers and might require a thicker intake gasket.
    • Stud Girdles - Due to many available factory OEM and aftermarket style/variations your existing stud girdle may not fit (AFR heads require AFR Stud Girdles)
    • Boosted/Nitrous Applications - We strongly recommend considering Inconel exhaust valves and AFR's optional heavy duty intake valve for power adder applications. Since boosted or nitrous oxide applications accelerate RPM quickly, additional spring pressure is required. We strongly recommend upgrading your valve springs or increasing your valve spring pressures since boost pressure on the valve reduces spring tension. For example, 15lbs boost on a 2.125 OD valve reduces the springs closed seat pressure by approximately 40-45lbs.
    • All MARINE Applications - We strongly recommend Inconel exhaust valves & also offer a hard anodized coating to slow the effects of corrosion. Please see note on guide clearance below.
    • Valve Guide Clearance - Your AFR Heads come with proper guide clearance (.0012"-.0016") for most applications. Boosted/Nitrous or marine applications might require additional clearance and it is the customer's responsibility to verify proper clearance in these applications.
    • Valve Springs - Forced induction, nitrous oxide and cams with aggressive ramp rates may require additional spring pressure. We offer optional valve springs for these types of applications. AFR also recommends the use of billet cam cores and short travel Hydraulic Roller lifters which tolerate higher spring loads. Please don't hesitate to contact us directly if you question which spring is correct for your application.
    • AFR Titanium Valves - Might require lash caps and different length pushrods. Titanium valves are coated, do not grind valves because it removes the protective coating.
    • Piston to Valve - AFR assumes no responsibility for damage if the end user builds an engine without properly verifying he has enough piston to valve clearance (depth and radial clearance both checked). We recommend a minimum depth of .080" on the intake valve and .100" on the exhaust with a radial clearance of .020" minimum around the perimeter of each valve. Clay is recommended to visually verify both depth as well as radial clearance. Just checking depth is not enough, the position of the valve pocket must also be addressed. It is the customers responsibility to verify proper piston to valve clearance.
    • CNC Porting - Occasionally a 100% CNC ported head might have a very small area left "as cast", this in no way affects performance.
    • Shaft Mount Rockers - Shaft mount rockers might require additional clearance for proper pushrod fitment. Do not clearance the push rod area as the wall is .060" thick. If you use Jesel Shaft Mounts, AFR only recommends their Pro Series.
    • Comp Cams Pro Magnum Rockers - Typically these rocker arms do not clear a 1.500" O.D retainer. A lash cap is required to space up the rocker arm.
    • Spring Installation - To ease installation with 1.550" O.D or larger springs, 12 pt head bolt or studs are recommended for extra clearance. Beveled or ground washers might be needed (ARP #200-8504 comes with smaller O.D and doesn't need to be ground)
    • Valve Spring Installed Heights - AFR valve spring installed height spec is +/- .015 which is the smallest shim available for adjustment.
    • Rocker Arms - Use full roller rocker arms, roller tip rockers with stock style bodies are NOT recommended.