Patriot Performance CNC Ported 243 LS6 / LS2 2.02"/1.57" 59cc Heads Assembled

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 2.02”/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: 2.02"
• 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