AFR's 325cc heads are designed feature partially CNC ported intake, exhaust, A356 aluminum castings and high quality components throughout. Recommended for more aggressive street, or street/strip builds with displacements up to 540 cubic inches, operating up to 6800 RPM. Also available with 100% CNC chambers for increased air flow (see chart). Component upgrades and machining options are available to customize AFR Heads to your specific build.
AFR's Best of Both Solution
Are you looking for big torque and big horsepower numbers? Our BB
Chevy line of medium volume intake runners will provide you with
exactly that. The phrase "having your cake and eating it to" would
certainly be appropriate with the moderately sized intake runners
producing tremendous flow figures across the entire lift range.
These high flow/high velocity ports provide extreme versatility
and fill the needs of many applications. From a max-effort high
compression 454 to a 605 CID low rpm marine application, these
aluminum cylinder heads would be a great choice. These heads would
also be ideal in a larger cubic inch "Pro-Street" application with
their broad torque range, as well as significant rpm and
horsepower capability. These cylinder heads will work best with a
primary operating range of 3000-7000 rpm's (This range is an
average and will vary with engine displacement as well as
component selection). The 325cc come standard with AFR’s trademark
.750" thick head deck, reinforced rocker stud bosses, and are
equipped with premium one piece stainless steel 2.300" intake
valves and 1.880" exhaust valves. Standard combustion chamber
volume is 115cc's on our 325 “As Cast” pieces, while the CNC
Chamber 325 version comes with a 121cc chamber. Properly selecting
the correct cylinder head for an application depends on a large
number of variables. Please consult with one of our sales
technicians to assist you in making the best decision for your
particular application
Note:
Optional stud girdle required for 2° rolled valve angles and 1"
longer head bolts needed on four bottom exhaust bolt holes. Longer
pushrods might also be required.
color="#ffffff" size="4">Basic Package Components |
color="#ffffff" size="4">Part # |
20%
CNC Ported Exhaust Ports
30% CNC Ported Intake Ports
50% CNC
Ported Combustion Chambers
Competition 5-angle Valve Job |
|
11/32" Intake Valve,
2.300" x5.500" O.A.L |
AFR #7626 |
11/32"
Nail
Head
Exhaust
Valve, 1.880" x 5.450" Overall Valve
Length |
AFR #7631 |
PAC Racing Spring #1224
1.625 O.D. Solid Roller, 275lbs on seat, .850 Maximum
Lift, Max RPM 7400-7600 |
AFR #8031
|
Manley 10° Steel
Retainers 1.500" O.D x 1.168" I.D x .844" I.D |
AFR #8518
|
10° 11/32" Valve Locks
with lashcap recess |
AFR #9005 |
ARP
7/16" Rocker Exhaust Studs |
AFR #6406 |
ARP 7/16" Rocker Intake
Studs |
AFR #6407 |
Adjustable
3/8"
Guide
Plates |
AFR #6109 |
11/32" Viton Valve
Seals |
AFR #6611 |
Hardened
Spring
Cup
1.740"
O.D
/ 1.650" I.D |
AFR #8046 |
Intake Valve Seats
2.450" O.D x 2.000" I.D x .375" Deep |
AFR #9062 |
Exhaust Valve
Seats 2.000" O.D x 1.580" I.D x .375" Deep |
AFR #9064 |
11/32" Intake Bronze Valve
Guides .531" O.D x 2.10" O.A.L |
AFR #9045 |
11/32" Exhaust
Bronze Valve Guides .531" O.D x 2.25" O.A.L |
AFR #9046 |
color="#ffffff" size="4">Specifications, Features, and
Optional Supporting Components |
Head Torque |
75 ft.
lbs |
Intake Port Gasket |
AFR
#6853
(.120"
Thick)
or AFR
#6855 (.060" Thick) |
Exhaust
Port
Gasket |
AFR #6858
|
Head Gasket, Fel-Pro
#1047 (Mark V and VI) |
AFR #6849 |
Head
Gasket, Fel-Pro #1017-1 (Mark IV) |
AFR #6350 |
Head Bolts, ARP
135-3703 (Mark IV) |
AFR #6306 |
Head
Bolts, ARP 135-3707 (Mark V) |
AFR #6308
|
Head Studs, ARP
235-4713 |
AFR #6307 |
Head
Bolt Washers, Manley |
AFR #6320 |
Suggested Manifold
|
Super
Victor Victor Jr.,
|
Spark Plug
Starting Range |
style="float: right;">Autolite 3932 |
Combustion Chambers |
121cc w/ CNC Chambers or 117cc w/ As Cast
Chambers |
Valve
Spring Pocket Diameter |
style="float: right;">1.725 O.D
|
Intake Port Dimension |
2.360"H
x
1.685"W
x 3/8 Radius |
Exhaust
Port
Dimension |
style="float:right;">1.720"H x 1.920" W |
Valve Angle |
24°/4°
Intake,
15°/4°
Exhaust |
Angle Mill
|
style="float:right;">.009" per cc/ Maximum 104cc as
cast or CNC Chamber |
Flat Mill
|
.006"
per
cc/
Maximum
108cc
as cast or 114cc CNC Chamber |
Stud
Girdle, (AFR Specific) |
AFR #6202
|
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. color="#000000" face="Arial">1" longer head bolts needed on
four bottom exhaust bolt holes. Angle mills might require a
.120 thick intake gasket.
