Patriot Performance 2013 - Patriot Performance GM LS2/LS6 CNC Ported Heads

Stage II Heads

Patriot Performance custom 5 axis CNC machined new GM castings make these heads a must have for any performance oriented GM LS series engine. These heads provide up to a 65 cfm improvement over stock OEM versions. The 64cc chambers will increase the compression on a stock LS1 from 10:1 to 10.5:1. The 59cc chambers (achieved by milling), will increase the compression on a stock LS1 from 10:1 to 11:1. Based on other modifications, gains of up to 40 rwhp can be expected. These are a great choice for naturally aspirated engines and applications where 75-150hp nitrous systems will be used. The assembled Stage II heads feature 21-4N 2.02''/1.57'' stainless steel valves, Original Patriot Gold Dual .650'' Lift springs, titanium retainers, Super 7 machined locks, custom honed bronze guides, machined spring bases, and viton rubber seals.
Sold as Pair



Technical Specs:
Combustion Chamber: 64cc or 59cc
Intake Runner: 227cc
Exhaust Runner: 70cc
Intake Valve: 2.02''
Exhaust Valve: 1.57''
Max. Valve Spring Lift: 0.650''
Spring Pressure Closed: 135 lbs. @ 1.800''
Spring Pressure Open: 375 lbs. @ 1.090''
Retainer Material: Titanium
Valve Seal Material: Viton
Valve Guide Material: Manganese Bronze
Valve Job: 5-angle

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Stage III Heads

Patriot Performance custom 5 axis CNC machined new GM castings make these heads a must have for any performance oriented GM LS series engine. These heads provide up to a 80 cfm improvement over stock OEM versions. The 64cc chambers are a great choice for 4.00'' and larger bore motors. These will work on both naturally aspirated and applications where forced induction or nitrous will be used. The Stage III heads feature 21-4N 2.08''/1.60'' stainless steel valves, Original Patriot Gold Dual .650'' Lift springs, titanium retainers, Super 7 machined locks, custom honed bronze guides, machined spring bases, and viton rubber seals.
Sold as Pair



Technical Specs:
Combustion Chamber: 64cc
Intake Runner: 227cc
Exhaust Runner: 70cc
Intake Valve: 2.08''
Exhaust Valve: 1.60''
Max. Valve Spring Lift: 0.650''
Spring Pressure Closed: 135 lbs. @ 1.800''
Spring Pressure Open: 375 lbs. @ 1.090''
Retainer Material: Titanium
Valve Seal Material: Viton
Valve Guide Material: Manganese Bronze
Valve Job: 5-angle