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Bare GM LS3 4 Bolt 276cc Aluminium Cylinder Heads with 70cc Chamber (Pair)
2.60" x 1.28" Intake Port, 1.47" x 1.64" Exhaust Port

The Aeroflow Series of Aluminium Cylinder Heads are taking affordable performance street and strip cylinder heads to the next level. These heads utilise ultra-smooth A356-T6 aluminium castings, new as-cast runner and chamber designs produce excellent flow numbers. This combined with a 5-angle competition valve job, diamond-honed bronze guides, hand bowl blending and professional assembly help to outperform some of the best brands in the business.

The Aeroflow Performance GM LS cylinder heads are designed for street / race performance engines to give the ultimate in flow at a competitive price. Made from A356 aluminium castings, these 15° LS3 Rectangle Port heads are designed to fit LS series engines with a 4.00" or larger bore. These bare 276cc heads accept 2.165" diameter intake valves and 1.60" exhaust valves and have a thicker than stock .625" deck thickness. Available in OE 4-bolt design or 6-bolt design to suit standard or LSX block designs.

Note: Thread sealant must be used on all rocker bolts as threads intersect with intake ports.

Head Specifications

Material:  A356 Aluminium
Chamber Chamber:  70cc
Intake Port Volume:  276cc
Intake Port Dimension:  1.285" x 2.60"
Exhaust Port Volume:  90cc
Exhaust Port Dimension:  1.47" H x 1.64" W
Spark Plug Location:  OE Stock
Intake Valve Diameter:  2.165" x 4.89"
Exhaust Valve Diameter:  1.59" x 4.89"
Valve Stem Diameter:  8mm
Valve Spring Pocket I.D.:  1.30"
Valve Guide Material:  Manganese Bronze
Valve Guide O.D.:  .502" (.560" at base)
Rocker Design:  LS3 Rails required
Valve Angle:  15°
Deck Thickness:  .625"


We recommend to check installed spring seat pressure & open pressure before installing your cylinder heads to make sure the spring pressure is correct for your application.

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