BBC

AFR Big Block Chevy 305cc Rectangle Port Magnum Aluminum Cylinder Heads

Product Description

AFR 305cc Partially CNC Ported “Magnum” BBC Head

AFR’s Torque Monster


BBC 305cc Partialially Ported

The smallest BBC Rec port intake volume runners in our line-up, but don’t let size fool you. Our partially ported 305cc with CNC bowl & chamber blend will provide you with flow numbers most medium sized cylinder 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. The 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. AFR 305cc cylinder heads would be a great choice if your looking for big torque, strong low rpm performance, and still have good rpm capabilities.

The 305cc comes 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 117cc’s on the 305cc partially ported
heads. 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.

Note:

Optional stud girdle required for 2° rolled valve angles and 1” longer head bolts needed on four bottom exhaust bolt holes.

305cc Partially Ported BBC Flow Chart

305cc BBC Cylinder Head Flow Chart

305cc Partially ported BBC with 100% CNC Chamber Flow Chart

305cc BBC Cylinder Head Flow Chart #2
305cc Rectangle Port Magnum Cylinder Head Features:

  • 50% Partially or 100% Fully CNC Ported Combustion Chambers
  • Bowl Blended Exhaust Ports
  • Bowl Blended Intake Ports
  • Competition 5-angle Valve Job
  • 305cc 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
2100 305cc Rectangle Port 24° Magnum Aluminum Cylinder Heads

  • BB-Chevy
  • 117cc Combustion Chambers
  • 50% CNC Combustion Chambers
  • Assembled
  • Sold in Pairs, 2/pkg.
2100-1 305cc Rectangle Port 24° Magnum Aluminum Cylinder Heads

  • BB-Chevy
  • 121cc Combustion Chambers
  • 100% CNC Combustion Chambers
  • Assembled
  • Sold in Pairs, 2/pkg.
3050 305cc Rectangle Port 24° Magnum Aluminum Cylinder Heads

  • BB-Chevy
  • 117cc Combustion Chambers
  • 50% CNC Combustion Chambers
  • Bare Head Only
  • Sold in Pairs, 2/pkg.
3050-1 305cc Rectangle Port 24° Magnum Aluminum Cylinder Heads

  • BB-Chevy
  • 121cc Combustion Chambers
  • 100% CNC Combustion Chambers
  • Bare Head Only
  • Sold in Pairs, 2/pkg.