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Vehicle Info NeededPROMAXX PERFORMANCEPART NUMBER: 723-3156A
XXTREME Assembled 255 cc Cathedral Port Cylinder Heads for LS1, LS2 w/4 in. Min. Bore w/59 cc Combustion Chambers
$2,66000
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Lowest Price GuaranteeLS1, LS2 w/4 in. Min. Bore [255 cc Cathedral Ports]
XXTREME Assembled Cylinder HeadsLS1, LS2 w/4 in. Min. Bore 255 cc Cathedral Ports 59 cc Combustion Chambers 2.125 in. Int./1.60 in. Exh. Valves Valve Angle: 11° Valve Springs: .650 in. Max Lift Retainers: Tool Steel Set of 2
ProMaxx 3156A XXTREME Assembled Cylinder Heads Features:
- High-flow as-cast port design
- Ultra-smooth 356-T6 aluminum casting
- 21-4N stainless 1 piece swirl polished back cut valves
- 5-angle valve job
- 11-Degree valve angle
- Hardened steel valve seats
- OEM LS3 valve spacing
- Manganese bronze diamond honed guides
- Viton valve seals
- Built-in raised valve cover rail
- .750 in. deck thickness
- Billet LS3 OEM rocker stand
- For use with standard or 6 bolt pattern
- Large spring pockets
ProMaxx 3156A XXTREME Assembled Cylinder Heads Notes:
- Requires 4 in. minimum engine cylinder bore
- Requires LS3 intake rocker arms
- Included valve springs with tool steel retainers specs:
- Closed: 155 lbs. @ 1.800 in.
- Open: 425 lbs. @ 1.150 in.
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
Part TypeCylinder Head
BrandPROMAXX PERFORMANCE
Part CategoryPerformance Parts
Cylinder Head MaterialAluminum
Exhaust Valves IncludedYes
Locks IncludedYes
Engine Make/SizeGM Gen III/IV LS
Retainers IncludedYes
Intake Port ShapeCathedral
Guideplates IncludedNo
Cylinder Head FinishNatural
Intake Valve Angle11
Maximum Valve Lift0.65 in (16.5 mm)
Valve Seat MaterialSteel
FinishNatural
Valve Springs IncludedYes
Valve Seat Machine Style5-angle
Cnc-Machined Intake RunnerNo
Intake Valves IncludedYes
QuantitySold as a set of 2
Valve Stem Seals IncludedYes
Intake Valve Diameter2.125 in (53.975 mm)
Accessory Bolt Holes DrilledYes
Valve Guide MaterialManganese bronze
Combustion Chamber Volume (Cc)59
Exhaust Valve Angle11
Rocker Arm Studs IncludedNo
Cylinder Head StyleAssembled
Part FitmentSemi Universal
Valve Cover Mounting StyleCenterbolt
Retainer MaterialTool steel
Intake Runner Volume (Cc)255
Cnc-Machined Exhaust RunnerNo
Cnc-Machined Combustion ChamberNo
Exhaust Valve Diameter1.6 in (40.6 mm)
Vendor Part Number3156A
Package Qty1
Package TypeEA
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