AFR Big Block Chevy 315cc Rectangle Port Magnum Aluminum Cylinder Heads

Product Description

AFR 315cc Fully CNC Ported “Magnum” BBC Cylinder Head

AFR’s Torque Monster

BBC 315cc Fully CNC ported Magnum Cylinder Heads

The smallest intake volume runners in our line-up, but don’t let size fool you. Our fully CNC ported 315cc aluminum cylinder heads will provide you with flow numbers most medium
sized heads, and some larger, can only dream about. This line was designed to optimize low and mid-lift airflow, while still generating impressive peak figures. Their application should be focused on
smaller cubic inch Big Blocks (396-502), with a primary operating range of 2500-6800 rpm’s (this range is an average and will vary with engine displacement as well as component selection). These
heads should also be given strong consideration in larger street driven or marine applications up to 555 CID, where low rpm power and drivability are a factor. The 315 version is extremely versatile
with its incredibly strong low and midlift airflow figures as well as peak numbers approaching the 400 CFM mark. These heads would be a great choice if your looking for big
torque, strong low rpm performance, and still have good rpm capabilities.
The 315cc come standard with AFR’s trademark .750” thick head deck, reinforced rocker stud bosses, and are equipped with premium one piece stainless steel 2.250”
intake valves and 1.880” exhaust valves. Standard combustion chamber volume is 121cc for our BBC 315cc. Take note the higher flowing exhaust ports and bolt pattern are raised .375 (3/8″) over stock location, this rarely affects header or chassis fitment.

Properly selecting the correct aluminum cylinder head for an application
depends on a large number of variables. Please consult with one
of our sales technicians to help 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.

315cc BBC CNC Aluminum Cylinder Head Flow Chart

315cc BBC Cylinder Head Flow Chart
315cc Rectangle Port Magnum Cylinder Head Features:

  • 100% CNC Ported Combustion Chambers
  • 100% CNC Ported Exhaust Ports
  • 100% CNC Ported Intake Ports
  • Competition 5-angle Valve Job
  • 315cc Intake Ports
  • Intake Valve, 2.250” x 5.500” Overall Valve Length
  • Exhaust Valve, 1.880” x 5.448” Overall Valve Length
  • 1.625” OD PAC Racing Solid Roller Valve Spring, 275 lbs on seat, .850” maximum lift
  • 10° Manley 4140 Chrome Moly Retainers
  • 10° Valve Locks
  • 7/16” Rocker Studs
  • Adjustable 3/8” Guide Plates
  • Viton Valve Seals
  • Hardened Spring Seats
  • Intake Valve Seats
  • Exhaust Valve Seats
  • Bronze Valve Guides


2000 315cc Rectangle Port 24° Magnum Aluminum Cylinder Heads

  • BB-Chevy
  • 121cc Combustion Chambers
  • Assembled
  • Sold in Pairs, 2/pkg.
3150 315cc Rectangle Port 24° Magnum Aluminum Cylinder Heads

  • BB-Chevy
  • 121cc Combustion Chambers
  • Bare Head Only
  • Sold in Pairs, 2/pkg.