Frankenstein LSA/LS3 M311 6 Bolt Heads

• Fully CNC ported, 72cc chamber volume
• 273cc intake port, 112cc exhaust port and 11° valve angle
• High Quality Components:
  • Black Nitride Stainless Steel Severe Duty Valves
  • Custom PAC .700” Lift Valve Springs
  • Titanium Retainers
• O-Ringed Exhaust Ports (Hi-Temp Silicone O-rings Included)
  
• Sold Per Set and Assembled

Price listed is for the pair
Castings:

• 6 Bolt Head
• 0.750″ Deck Structure
• OEM/Factory Style Water Crossover Ports
• 7/16″ Stud Size For Main 10 Bolts
• 8mm Stud Size For Outer Tabs and Deck Studs

Their Process:

• 5-Axis CNC Ported Intake Ports, Exhaust Ports, and Combustion Chambers
• Precision 5-Angle CNC Valve Job
• PCD Deck Milled
• Hand Blended and Deburred
• Final Wash
• Final Assembly with Spring Heights Checked
• Quality Control at every stage of manufacturing

Options/Components:

• FED Billet Rocker Stands For Stock LS3 Rockers
• Intake Valve Guides – Bronze
• Exhaust Valve Guides – Bronze
• Manley Polished Nextek HP Dual Spring 1.295″ 155# @ 1.800/405# @1.150/.660 lift (Hydraulic)
• FED Titanium Retainers
• ¼ x ½ Dowel Pin – Rocker Stand Dowel Pins
• Exhaust Port Silicone O–Rings
• Intake Valve Seats – Ductile Iron
• Exhaust Valve Seats – Ductile Iron
• FED Steel Valve Spring Locators – .565 Guide
• Stock Style 7° Valve Locks
• US Seal Viton High Heat Valve Stem Seals
• US Seal Hardened Spring Shims