Patriot Performance GM LS6 / LS2 Style Stage II Head Assy (2.055/1.57/59cc).
Our 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 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. The Stage II heads feature 21-4N 2.055”/1.57” stainless steel valves, our 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: 59cc
- Intake Runner: 227cc
- Exhaust Runner: 70cc
- Intake Valve: 2.055"
- 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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