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AFR 345cc BBC Magnum "As Cast" Cylinder Heads

These are the *BRAND NEW* Magnum AFR 345 cc "As Cast" Rectangle Port BBC aluminum cylinder heads.

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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, 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 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 application.

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.

Basic Package Components Part #
5-angle valve job
Intake Valve, 2.300" stainless steel
AFR #7626
Exhaust Valve, 1.880" stainless steel AFR #7631
1.625 O.D. Solid Roller PAC Racing Spring, 275lbs on seat, .850 Maximum Lift AFR #8031
10° Chrome Moly Retainer AFR #8518
10° Valve Locks AFR #9005
Guide Plates AFR #6109
Viton Valve Seals AFR #6611
Hardened Spring Cup AFR #8046
Intake Valve Seats AFR #9062
Exhaust Valve Seats AFR #9064
AFR BB Chevy 7/16 Exhaust Studs AFR #6406
AFR BB Chevy 7/16 Intake Studs AFR #6407

Specifications, Features, and Optional Supporting Components
Head Torque 75 ft. lbs
Intake Port Gasket, 1.720" x 2.450" with 1/2" radius, Fel-Pro #1275 AFR #6856
Exhaust Port Gasket AFR #6858
Head Gasket AFR #6850
Head Studs AFR #6307
Head Bolts AFR #6308
Head Bolt Washers AFR #6320
Stud Girdle AFR #6210
Suggested Manifold Dart #6200, #6201, & #6203
Suggested Manifold Brodix HVH #2000, #2001, #2005, & #2006
Spark Plug Starting Range Champion C59C Autolite 3932
Combustion Chambers 115cc As Cast, 121 w/ CNC Chambers
Spring Pocket Can be cut to 1.750, no deeper
Valve Spacing Standard
Rocker Arms Standard
Valve Angle 24°/4° Intake, 15°/4° Exhaust
Angle Mill (Milling options available) 104cc max
.009" per cc
Flat Mill (Milling options available) As Cast 108cc max, CNC 114cc max
.006" per cc
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. Angle mills might require a .120 thick intake gasket.


Shipping Information

  • Item Requires Shipping
  • 80.0 lbs.
  • W24.0000” x H12.0000” x L24.0000”
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  • This item ships in its own box.
  • FREE continental USA ground shipping on ALL AFR Cylinder Heads

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