JEGS 555-514310 Big Block Chevy Aluminum Cylinder Head Features:

• Combustion Chamber Volume: 135 cc
• Intake Runner Volume: 365 cc
• Exhaust Runner Volume: 156 cc
• Cylinder Head Style: Assembled
• Cylinder Head Material: Cast aluminum
• Camshaft Style: Hydraulic roller
• Intake Port Shape: Rectangular
• Intake Port Dimensions: 2.510 in. x 1.820 in.
• Intake Valve Diameter: 2.250 in.
• CNC-Machined Combustion Chamber: Yes
• CNC-Machined Intake Runner: Yes
• CNC-Machined Exhaust Runner: Yes
• Combustion Chamber Style: Heart
• Intake Port Location: Standard
• Exhaust Port Shape: Rectangular
• Exhaust Port Dimensions: 1.690 in. x 1.900 in.
• Exhaust Port Location: Raised
• Spark Plug Style: Angle
• Spark Plug Thread Size: M14 x 0.750
• Spark Plug Seat Style: Gasket
• Intake Valves Included: Yes
• Exhaust Valves Included: Yes
• Exhaust Valve Diameter: 1.880 in.
• Valve Springs Included: Yes
• Installed Height: 2.000 in.
• Seat Pressure at Installed Height: 260 lbs.
• Open Height: 1.250 in.
• Open Pressure: 700 lbs
• Valve Spring Coil Bind Height: 1.200 in.
• Maximum Valve Lift: 0.750 in.
• Outside Diameter of Outer Spring: 1.620 in.
• Number of Springs Per Valve: Dual
• Retainers Included: Yes
• Retainer Material: Chromoly steel
• Locks Included: Yes
• Lock Style: 10 degree
• Valve Stem Seals Included: Yes
• Valve Stem Seal Style: Positive stop
• Rocker Arms Included: No
• Rocker Arm Nuts Included: No
• Guideplates Included: No
• Valve Cover Mounting Style: Perimeter bolt
• Accessory Bolt Holes Drilled: Yes
• Intake Valve Angle: 24/4
• Exhaust Valve Angle: 15/4
• Valve Guides Included: Yes
• Valve Guide Material: Bronze
• Valve Seats Machined: Yes
• Valve Seat Machine Style: 5-angle
• Valve Seat Material: Ductile iron
• Cylinder Head Color: Natural
• Steam Holes Drilled: No
• Machined for O-Ring: No
• Remanufactured: No
• Notes: Exhaust port is raised 0.357 in. over stock. Recommend guide plates Dart# 27001230-4 or AFR# 6110-1.

Emissions Note:

This part is only legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles or on vehicles used solely for the purposes of closed competition racing.

CLICK THIS LINK FOR IMPORTANT CARB & EPA EMISSIONS INFORMATION ABOUT THIS PART