AFR LSX Mongoose street high-flow aluminum cylinder heads are specifically designed for 3.900" bore engines and are emissions legal. E/O # D250-4. The LSX Mongoose High Flowing Strip cylinder heads are specifically designed for 4.000" or larger bore engines. Both styles feature CNC-ported intake and exhaust ports. All heads are sold as pairs, com-pletely assembled (unless specified as bare) with stainless valves, valve springs, retainers, locks, and seals.
- Cylinder Head Style:
- Assembled
- Cylinder Head Material:
- Cast aluminum
- Cylinder Head Finish:
- Natural
- CNC-Machined Combustion Chamber:
- Yes
- Combustion Chamber Volume (cc):
- 64cc
- Combustion Chamber Style:
- Heart
- CNC-Machined Intake Runner:
- Yes
- Intake Runner Volume (cc):
- 215cc
- Intake Port Shape:
- Cathedral
- Intake Port Location:
- Standard
- Intake Valve Angle:
- 15 degree
- CNC-Machined Exhaust Runner:
- Yes
- Exhaust Runner Volume (cc):
- 84cc
- Exhaust Port Shape:
- Square
- Exhaust Port Location:
- Standard
- Exhaust Valve Angle:
- 15 degree
- Intake Valves Included:
- Yes
- Intake Valve Diameter (in.):
- 2.020 in.
- Exhaust Valves Included:
- Yes
- Exhaust Valve Diameter (in.):
- 1.600 in.
- Valve Type:
- Stainless
- Maximum Valve Lift (in.):
- 0.600 in.
- Valve Springs Included:
- Yes
- Valve Spring Type:
- Dual W/Damper
- Outside Diameter of Outer Spring (in.):
- 1.290 in.
- Valve Guides Included:
- Yes
- Valve Guide Material:
- Bronze
- Valve Seats Machined:
- Yes
- Valve Seat Material:
- Ductile iron
- Valve Seat Machine Style:
- 3-angle
- Retainers Included:
- Yes
- Retainer Material:
- Titanium
- Valve Stem Seals Included:
- Yes
- Valve Stem Seal Style:
- Viton Positive stop
- Locks Included:
- Yes
- Lock Style:
- 7 degree chromoly
- Camshaft Style:
- Hydraulic roller
- Spark Plug Style:
- Angled
- Guideplates Included:
- No
- Guideplate Pushrod Size:
- 3/8 in.
- Rocker Arm Studs Included:
- No
- Rocker Arm Nut Thread Size:
- N/A
- Accessory Bolt Holes Drilled:
- Yes
- Valve Cover Mounting Style:
- Centerbolt
- Heat Crossover:
- Yes
- Steam Holes Drilled:
- No
- Oiling Style:
- Through pushrod
- Machined for O-Ring:
- No
- Quantity:
- Sold as a pair.
- Notes:
- Requires minimum 3.900 in. diameter bore size for intake valve clearance. These cylinder heads do not have provisions for perimeter bolt valve covers.
- Make:
- Chevrolet
- Engine Family:
- Chevy small block Gen III/IV (LS-based engines)
- Engine Sizes:
- 5.7L/350-7.0L/427
- Years:
- 1997-2019
