LT4 Single Black Label Head - 4.065 (+) Bore - For Direct Injection - 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: 4.065" (+)
• Weight: 30 lbs.
• Intake Valve Size: 2.165"
• Exhaust Valve Size: 1.600"
• Valve Stem Diameter: 5/16"
• Valve Length: 5.550"
• Intake Valve Angle: 12.5°x2.5°
• Exhaust Valve Angle: 12°x2.5°
  
• Valve Spring Pocket Diameter: 1.400"
• Valve Spring Install Height: 1.800"
• Head Stud Size: .530"
• Valve Guide OD: .570"
• Valve Job Type: Newen CNC 5 Angle

Air Flow & Performance Criteria

• Intake Max. Flow: 355 CFM @ 0.700"
• Exhaust Max. Flow: 224 CFM @ 0.700"
• Intake Average Flow: 247 CFM
• Exhaust Average Flow: 163 CFM
• Intake Seat Material: Ductile Iron
• Intake Port Volume: 292cc
• Exhaust Port Volume: 111cc
• Standard Chamber Volume: 60cc
• Port Type: CNC
  

Materials

• Cylinder Head Material: A356-T6 Aluminum
• Intake Valve Seat Material: Ductile Iron
• Exhaust Valve Seat Material: Ductile Iron
• Deck Thickness: .750"
• Rocker Stand Type: Pedestal
• Rocker Arm Type: LS7 Exhaust 1.8 Ratio
• Guide Material: Phosphor Bronze

General

• Rocker Stand Type: Pedestal
• Rocker Stands Included: Built-In
• Rocker Stand Dowels Included: N/A
• Uses Stock Rocker Bolts: No
• Rocker Bolts Included: No
• Rocker Arm Type: LS7 Exhaust 1.8 Ratio
• Head Bolt QTY: 4 Bolt Style
• Valve Cover Rail Height: + ½ inch
• Can use OE Valve Cover: Yes

Custom Options Available

• Chamber Softening
• Custom Chamber Sizing
• ½ inch head stud clearance
• Copper Exhaust & Intake Valve Seats