Small Block Chev 327 350 400 204cc Complete Aeroflow Performance Aluminium Cylinder Heads with 67cc Chamber (Pair)

Aeroflow has become synonymous with premium quality performance products. Aeroflow's objective has been to incorporate state-of-the-art manufacturing, aerospace quality materials and rigid quality controls to produce quality performance products at extraordinary value. Aeroflow has taken its forward thinking knowledge to the street, manufacturing a wide range of race quality products to improve street performance and dependability.

The cylinder head sits on top of the engine and seals the top of the engine’s cylinders creating the combustion chamber – the place where the fuel and air mixture is burned. The passages in the cylinder head – known as the ports, allow for air and fuel to flow into the cylinder and exhaust gases to flow out of it. The head also channels coolant into the engine block, cooling down the engine components. It’s also the housing for the valve gear, springs, lifters, and spark plugs.

Most OEM cylinder heads are made from cast iron which is durable and cheap to manufacture, but heavier and not efficient at dissipating heat.

The Aeroflow Performance aluminium cylinder heads utilise high-quality ultra-smooth A356-T6 aluminium castings and new as-cast runner and chamber designs that produce increased power & torque, improved efficiency, and excellent flow numbers.

Designed for both street and race performance engines, these new as-cast runner and chamber designs produce excellent flow numbers. This combined with a 5-angle competition valve job, diamond-honed bronze guides, hand bowl blending and professional assembly help to outperform some of the best brands in the business.

These 204cc cylinder heads are ideal for operating in the idle to 6500rpm range, and will fit a 4.00" bore and larger. They also include larger than stock 1.43" diameter valve springs, able to handle up to .575" maximum lift. Suit flat tappet and hydraulic camshafts.

The complete heads include intake valves, exhaust valves, valve springs, valve retainers, valve locks, valve seals, rocker arm studs, and push rod guide plates.

Specifications:

• Part number: AF95-2350
• Material: A356-T6 Aluminium
• Chamber: 67cc
• Intake Port Volume: 204cc
• Intake Port Dimension: 2.22" x 1.31"
• Exhaust Port Volume: 70cc
• Exhaust Port Dimension: 1.34" H x 1.39" W
• Spark Plug Location: Straight
• Intake Valve Diameter: 2.02"
• Exhaust Valve Diameter: 1.60"
• Valve Stem Diameter: 11/32"
• Valve Spring Pocket I.D.: 1.49"
• Valve Guide Material: Manganese Bronze
• Valve Guide O.D.: .530" (.570" at base)
• Rocker Stud Thread Size: 7/16" x 14
• Valve Angle: 23°
• Deck Thickness: .625"

 

Installed components

• Intake Valves: 2.02" x 4.91" x 11/32", part no. AF59-3501
• Exhaust Valves: 1.60" x 4.91" x 11/32", part no. AF59-3502
• Valve Springs: 1.43" Single (with damper), part no. AF59-3503
• Valve Retainers: 7° 11/32", part no. AF59-3504
• Valve Locks: 7° 11/32" part no. AF59-3505
• Valve Seals: 11/32" x .530"
• Rocker Arm Studs: 7/16"-14 x 7/16"-24, part no. AF59-3506
• Push Rod Guide Plates: 5/16" Flat, part no. AF59-3507

 

Valve Spring Specifications

• Installed Height: 1.790"
• Installed Pressure: 135lbs
• Open Pressure: 290lbs @ 500"
• Maximum Lift: .540" @ 1.250"
• Coil Bind: 1.210"
• Spring Outside Diameter: 1.450"
• Spring Inside Diameter: 0.700"
• Spring Free Length: 2.350"
• Valve Spring Retainer Outside Diameter: 1.400"
• Valve Spring Inside Diameter: 0.395"
• Valve Spring Retainer Step 1: 1.060"
• Valve Spring Retainer Step 2: 0.680"
• Valve Spring Locator Outside Diameter: 1.560"
• Valve Spring Locator Inside Diameter: 0.560"

 

Fitment notes:

• It’s recommended to check the installed spring seat pressure & open pressure before installing your cylinder heads to make sure the spring pressure is correct for your application.
• The installed larger than stock 1.43" diameter valve springs, able to handle up to .575" maximum lift
• Suggested Components
  • Head Gasket: Fel-Pro 1003
  • Intake Gasket (1.31 x 2.22 Port Size): Fel-Pro 1206
  • Exhaust Gasket (1.34 x 1.39 D Port Size): Fel-Pro 1406
  • Head Bolts: ARP 134-3601 or 134-3701
  • Head Studs: ARP 134-4001 or 234-4301
  • Spark Plugs (14mm x 3/4" reach with flat gasket seat): Champion RC9YC