AFR's 345cc heads are designed features the CNC Chambers and an optional up-gradable partially CNC ported intake & exhaust, A356 aluminum castings and high quality components throughout. Recommended for more radical street/strip, "Pro Street", or racing builds with displacements up to 572 cubic inches, operating up to 7000 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 "As Cast" Magnum Series
If "Dirty Harry" drove a racecar, it would certainly be fitted
with a pair of our 345 or 357 "Magnum" cylinder heads. If huge
horsepower is what you are searching for, either of these castings
will certainly deliver. With our Race Ready "As Cast" 345cc
flirting with 400 CFM and our fully CNC ported 357cc flowing 425
CFM, these heads represent the ultimate in airflow for your BB
Chevrolet. These heads were targeted at larger cubic inch engines
(509-632 CID) looking for maximum horsepower and rpm capability
with a primary operating range of 3500-8000 rpm's (This range is
an average and will vary with engine displacement and component
selection). These heads will also provide impressive torque
figures at higher rpm levels. Blown, turbo, and nitrous engines
will especially like the larger, higher flowing intake ports.
These heads will work best with camshafts exceeding .750 gross
valve lift to make better use of the substantial airflow found in
the higher lift range. The 345cc heads come standard with AFR's
trademark .750" thick head deck, and reinforced rocker stud
bosses. Standard combustion
chamber volume is 115cc's on the 345 "As Cast" model. Properly
selecting the correct cylinder head 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 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.
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 # |
Competition
5-angle
Valve Job
50% CNC Ported Combustion Chambers
|
|
color="#ffffff" size="4">Specifications, Features, and
Optional Supporting Components |
Head Torque |
75 ft.
lbs |
Intake Port Gasket |
AFR
#6854
(.120" Thick) or AFR
#6856 (.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 & 117cc w/ As Cast
|
Valve
Spring Pocket Diameter |
style="float: right;">1.725 O.D
|
Intake Port Dimension |
2.435"H
x
1.765"W x 13/32 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: color="#000000" face="Arial">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.
Note: color="#000000" face="Arial">Angle mills might require
a .120" thick intake gasket. color="#000000" face="Arial">
