LS3 295cc 4.125" (+) Bore - Single Black Label CNC Cylinder Head - Bare

--->Download the cylinder head spec sheet<---- The Mast Motorsports cylinder head product line is completely manufactured from a raw casting to a finished cylinder head in the USA located in Nacogdoches Texas.  Mast refuses to compromise on materials and methods that may jeopardize longevity, performance, and quality.  When buying Mast Cylinder heads, you are getting the highest level of quality and performance on the market.  Full Send, no compromises, no shortcuts, ever. Dimensional Specs Bore Size: 4.125" (+) Weight: 27.5 lbs. Intake Valve Size: 2.250" Exhaust Valve Size: 1.600" Valve Stem Diameter: 5/16" Valve Length: 5.450" Valve Angle: 12° Valve Spring Pocket Diameter: 1.65" Valve Spring Install Height: 1.800" Head Stud Size: .493" Valve Guide OD: .502" Valve Job Type: Newen CNC 5 Angle Air Flow & Performance Criteria Intake Max. Flow: 397 CFM @ 0.700" Exhaust Max. Flow: 248 CFM @ 0.700" Intake Average Flow: 254 CFM Exhaust Average F