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Chevrolet Performance 88958684

R0X Splayed-Valve Aluminum Cylinder Head, Rough Machined

Chevrolet Performance 88958684
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Estimated to ship on 06/05/18
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Chevrolet Performance 88958684 R0X Splayed-Valve Aluminum Cylinder Head, Rough Machined $987.53
R0X Splayed-Valve Aluminum Cylinder Head
  • Rough Machined: Main surfaces & exhaust bolt pattern

  • Chevrolet Performance 88958684 Details

    R0X 4.500" Bore Spacing

    Rough Machined Detail
  • Machined: Main surfaces and exhaust bolt pattern
  • Not Machined: Head bolt & dowel holes, intake bolt holes, spark plug holes & pushrod holes, valve guides, valve seats, valve spring seats and rocker stands
  • Valve locations and angles may be relocated

  • "Cubed" bare head (no seats or guides & combustion chamber is unfinished)
  • Great for NHRA competition with dual carburetors
  • 240cc "as-cast" peanut intake ports
  • 78cc "as-cast" peanut exhaust ports

  • Specifications:

    Manufacturer's Part Number:

    These small block Chevy splayed-valve aluminum cylinder heads are a radical departure from standard in-line valve heads. Their splayed-valve arrangement angles both the intake and exhaust valves inward toward the center of the combustion chamber, allowing maximum valve sizing to dramatically improve airflow without increasing bore diameter. Castings have a 0.240" minimum port wall thickness so, for even greater flow, extensive modifications can be made. Sold individually, these aggressive all-out competition cylinder heads are designed to get the most power from your small block Chevy with no regard for "streetability." NHRA Competition Eliminator participants routinely produce over 1000 horsepower (naturally aspirated) with these race cylinder heads.

  • 355-T7 aluminum
  • No valve seats or guides
  • "As-Cast" Intake Ports: 240cc
  • "As-Cast" Exhaust Ports: 78cc
  • Extra-thick deck for angle or heavy flat milling
  • Valve spring pads accommodate 1.625'' springs
  • Modified Valve Angles: 16° x 4° Intake, 11° x 4° Exhaust
  • 4.400'' Bore Spacing: 45cc "As-Cast" Combustion Chambers
  • 4.500'' Bore Spacing: 40cc "As-Cast" or Unfinished Combustion Chambers
  • Spark plug location revised for angled 14mm, 5/8" hex, 3/4" reach, gasket seat plugs
  • Designed for longer-than-stock 2.200''/1.650'' valves and aftermarket shaft-mount rocker systems

  • Valve Cover Gaskets #809-10185043
  • Intake Manifold Gaskets #809-10185042
  • Custom-fabricated valve covers and intake manifold

  • Items You Need
    Some parts are not legal for use in California or other states with similar laws / regulations