Product Description
AFR 12° LS3 4-Bolt Cylinder Heads 260cc – Fully CNC Ported, 69cc Chambers, Assembled (Pair)
In Stock, Ready to Ship!
AFR's 260cc LS3 Mongoose cylinder heads feature 100% CNC ported intake runners, exhaust runners, and combustion chambers using advanced engineering and flow techniques to produce the ultimate Rectangle Port head available today. Featuring high strength A356 aluminum castings, titanium retainers and the highest quality components throughout. They're designed for 4.000" or larger bore applications up to 454 CI. These heads deliver exceptional airflow and combustion efficiency, making them ideal for racing applications as well as high performance street builds.
Included Components:
- 100% CNC Ported Combustion Chambers - 69cc
- 100% CNC Ported Intake (260cc) & Exhaust (95cc) Ports
- Competition 5-angle Valve Job
- 8mm Bead Lock Intake Valve, 2.165" Diameter x 5.200" Overall Valve Length
- 8mm Bead Lock Exhaust Valve, 1.600" Diameter x 5.205" Overall Valve Length
- PAC Racing Spring 1.270" OD Hydraulic Roller Dual Valve Spring, 155 lbs. on seat, .650” maximum lift
- 7° Titanium Retainers 1.245" O.D x .885" I.D x .655" I.D
- 7° Bead Lock Valve Keepers
- Viton Valve Seals .600" O.D x .495" I.D
- Hardened Valve Spring O.D Locator 1.380" O.D x .570" I.D
- Ductile Iron Intake Valve Seats 2.200" O.D x 1.750" I.D x .375" Deep
- Ductile Iron Exhaust Valve Seats 1.650" O.D x 1.350" I.D x .375" Deep
- 8 mm Bronze Valve Guides .502" O.D x 2.100" O.A.L
- Rocker Stands: Includes AFR rocker stands made specifically for these heads. Cannot use stock OEM rocker stands or shaft kits made for standard LS3 valve spacing.
Specifications & Features:
- Minimum Bore Diameter: 4.000"
- Material: A356 Aluminum
- Intake Port Volume: 260cc
- Intake Port Dimension: 2.610"H x 1.300"W x 7/16° Radius
- Intake Port Location: Stock
- Exhaust Port Volume: 95cc
- Exhaust Port Dimension: 1.540" H x 1.760" W
- Exhaust Port Location: Stock
- Combustion Chamber Size: 69cc
- Valve Cover Bolt Pattern: Center Bolt
- Valve Angle: 12°
- Valve Spring Pocket Diameter: 1.490" O.D
- Max Valve Spring Pocket Machining: 1.510" O.D
- Deck Thickness: .750"
- Spark Plugs: Accepts 14mm x .750" Gasket Seat, or 14mm x .708" Reach Taper Seat Plugs
- Head Bolt Pattern: Standard 4-bolt per cylinder LS pattern
Heads Sold/Priced as a pair.
