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STS BB-4 XTRA Series Cylinder Heads390cc Intake Port Volume 1.645'' Diameter Valve Springs - 945# Open, 330# Closed Spring Pressure 100% CNC Ported
- STS BB-4 XTRA Series Cylinder Head
- CNC Ported
- 390cc Rectangle Intake Ports
- 115cc Combustion Chambers
- 2.350'' Intake / 1.900'' Exhaust Valves
- 1.645'' Dia. Springs - 330# Seat Pressure
- Titanium Retainers
- Assembled, 1/pkg.
Cylinder Head Specifications - Intake Port Volume: 390cc - Rectangle Port
- Combustion Chamber Volume: 115cc
- Valves: 2.350' dia. x 5.568' o.a.l. Intake / 1.900' dia. x 5.494' o.a.l. Exhaust ( 11/32' Stem Diameter )
- Valve Springs: 1.645' Diameter - Open Pressure: 945 lbs.; Closed Pressure: 330 lbs.; Installed Height: 2.100'; Max Lift: .875'
- Spring Retainers: 1.645' 10° Titanium
- Rocker Studs: 7/16'
- Guide Plates: 3/8'
- Valve Seals: 11/32'
- Spark Plug Configuration: AngledFacts and Related Components
- Torque Heads: 70 ft-lb.
- Torque Rocker Studs: 40-45 ft-lb.
- Intake Gasket: Brodix p/n 158-MG2001, Cometic 245-C5428, Fel-Pro 375-1252-3
- Head Gasket: 4.540' Bore - Fel-Pro p/n 375-1017, Cometic p/n 245-C5433; 4.600' Bore - Fel-Pro p/n 375-1057, Cometic p/n 245-C5434
- Exhaust Gasket: Fel-Pro p/n 375-1411 or Cometic p/n 245-C5429
- Head Bolts: ARP p/n 070-135-3606, Manley p/n 660-42192
- Head Studs: ARP p/n 070-235-4702 (12-point)
- Spark Plug Specs: 14mm Thread, .750' (3/4') Reach, Gasket Seat
- Valve Angle: 24° and 4° Intake, 15° and 4° Exhaust
- Angle Milling: .0066' per cc
- Flat Milling: .0050' per cc
- Pushrod Slots: Standard
- Pushrods: Check pushrod clearance with head installed on the engine block before final assembly
- Stud Girdle: Standard
- Rocker Arms: Standard
- Lifters: Standard
- Pistons: 2° Valve Rolled Piston
- Valve Centerline: Standard
- Exhaust Pattern: Raised .600'
- Spring Pockets: May not be cut any larger or deeper than 1.625'
- Accessory Bolt Holes are Drilled
- Recommended Intake Manifold: Brodix SA 2012 (p/n 158-SA2012) / SA 2020 (p/n 158-SA2020)
Part TypeCylinder Head
BrandBRODIX
Part CategoryPerformance Parts
Cylinder Head MaterialAluminum
Intake Port LocationRaised
Rocker Arm Nut Thread Size (In.)7/16"-20
Exhaust Valves IncludedYes
Locks IncludedYes
Retainers IncludedYes
Lock Style10 degree
Guideplates IncludedYes
Rocker Arms IncludedNo
Oiling StyleThrough pushrod
Rocker Arm Nuts IncludedNo
Cylinder Head FinishNatural
Valve Seats MachinedYes
Intake Valve Angle24
Maximum Valve Lift0.8 in (20.32 mm)
Valve Seat MaterialDuctile iron
Heat CrossoverNo
Number Of Springs Per ValveTriple
Valve Springs IncludedYes
Valve Seat Machine Style3-angle
Damper Spring IncludedYes
Valve Guides IncludedYes
Cnc-Machined Intake RunnerYes
Intake Valves IncludedYes
QuantitySold individually
Valve Stem Seals IncludedYes
Intake Valve Diameter2.35 in (59.69 mm)
Accessory Bolt Holes DrilledYes
Exhaust Port LocationStandard
Valve Guide MaterialPhosphorous bronze
Outside Diameter Of Outer Spring1.645 in (41.8 mm)
Combustion Chamber Volume (Cc)119
Machined For O-RingNo
Exhaust Valve Angle24
Steam Holes DrilledNo
Rocker Arm Studs IncludedYes
Cylinder Head StyleAssembled
Part FitmentSemi Universal
Valve Cover Mounting StylePerimeter bolt
Retainer MaterialTitanium
Intake Runner Volume (Cc)390
Cnc-Machined Exhaust RunnerYes
Cnc-Machined Combustion ChamberYes
Exhaust Valve Diameter1.9 in (48.26 mm)
Vendor Part Number2048105
Package Qty1
Package TypeEA
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