Identical to street legal 454-O cylinder Head, but with deleted exhaust crossover passage for more power. High-performance oval port head can help produce over 540 horsepower with 9.5:1 compression when used with the proper matching components. Intake valves are 2.19", exhaust valves are 1.88" and both are lighter, with smaller diameter (11/32") stems than original valves. Semi-open combus-tion chamber provides exceptional combustion efficiency with streetable compression ratios. Sold individually, bare or com-pletely assembled.
- Cylinder Head Style:
- Assembled
- Cylinder Head Material:
- Cast aluminum
- Cylinder Head Finish:
- Natural
- CNC-Machined Combustion Chamber:
- No
- Combustion Chamber Volume (cc):
- 110cc
- Combustion Chamber Style:
- Semi-open
- CNC-Machined Intake Runner:
- No
- Intake Runner Volume (cc):
- 290cc
- Intake Port Shape:
- Oval
- Intake Port Location:
- Standard
- Intake Valve Angle:
- 26 degree
- CNC-Machined Exhaust Runner:
- No
- Exhaust Runner Volume (cc):
- 110cc
- Exhaust Port Shape:
- Square
- Exhaust Port Location:
- Standard
- Exhaust Valve Angle:
- 26 degree
- Intake Valves Included:
- Yes
- Intake Valve Diameter (in.):
- 2.190 in.
- Exhaust Valves Included:
- Yes
- Exhaust Valve Diameter (in.):
- 1.880 in.
- Valve Type:
- N/A
- Maximum Valve Lift (in.):
- 0.700 in.
- Valve Springs Included:
- Yes
- Valve Spring Type:
- Dual W/Damper
- Outside Diameter of Outer Spring (in.):
- 1.550 in.
- Valve Guides Included:
- Yes
- Valve Guide Material:
- Manganese bronze
- Valve Seats Machined:
- Yes
- Valve Seat Material:
- Ductile iron
- Valve Seat Machine Style:
- 3-angle
- Retainers Included:
- Yes
- Retainer Material:
- Steel
- Valve Stem Seals Included:
- Yes
- Valve Stem Seal Style:
- Positive stop
- Locks Included:
- Yes
- Lock Style:
- 7 degree
- Camshaft Style:
- Hydraulic roller
- Spark Plug Style:
- Angled
- Guideplates Included:
- Yes
- Guideplate Pushrod Size:
- 3/8 in.
- Rocker Arm Studs Included:
- Yes
- Rocker Arm Nut Thread Size:
- 7/16-20 in.
- Accessory Bolt Holes Drilled:
- Yes
- Valve Cover Mounting Style:
- Perimeter bolt
- Heat Crossover:
- No
- Steam Holes Drilled:
- No
- Oiling Style:
- Through pushrod
- Machined for O-Ring:
- No
- Quantity:
- Sold individually.
- Notes:
- For Hydraulic roller camshafts. If using a domed piston check clearance before final assembly, spark plug location has been moved .150 closer to bore center, with a semi-open chamber design.
- Make:
- Chevrolet
- Engine Family:
- Chevy big block Mark IV
- Engine Sizes:
- 6.5L/396-7.4L/454
- Years:
- 1966-1990
- Engine Family:
- Chevy big block Gen V
- Years:
- 1991-1995
- Engine Family:
- Chevy big block Gen VI
- Years:
- 1996-2000
- Engine Sizes:
- 7.4L/454
