Proflow does not sacrifice quality for a low price- you get both with our aluminium cylinder heads. Our LS3 cylinder heads are designed for street / race performance engines to give the ultimate in flow at a competitive price. Cast from A356 aluminium, these 15° LS3 rectangle port heads are designed to fit LS series engines with a 4.00" or larger bore. These bare 275cc heads accept 2.165" diameter intake valves and 1.60" exhaust valves and have a 0.625" deck thickness. Suits 6-bolt standard or LSX block designs.

Specifications:

• Specifications:

• Material:  A356 Aluminium
• Combustion Chamber:  70cc
• Intake Port Volume:  260cc
• Intake Port Dimension:  1.285" x 2.60"
• Exhaust Port Volume:  100cc
• Exhaust Port Dimension:  1.47" H x 1.64" W
• Spark Plug Location: OE 
• Intake Valve Diameter: 2.145" x 4.89"
• Exhaust Valve Diameter: 1.60" x 4.89"
• Valve Stem Diameter:  8mm
• Valve Spring Pocket I.D.:  1.30"
• Valve Guide Material:  Manganese Bronze
• Valve Guide O.D.:  0.502" (.560" at base)
• Rocker Design: LS3 Rails required
• Valve Angle: 15°
• Deck Thickness: 0.625"