Mast Black Label 255CC LS3 Bare Cylinder Heads - Sold in Pairs

MAST BLACK LABEL 255CC LS3 BARE CYLINDER HEADS - SOLD IN PAIRS - CH-LSX-600210
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: 4.000" (+)
Weight: 28 lbs.
Intake Valve Size: 2.165"
Exhaust Valve Size: 1.600"
Valve Stem Diameter: 5/16"
Valve Length: 5.450"
Valve Angle: 11°
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: 370 CFM @ 0.700"
Exhaust Max. Flow: 243 CFM @ 0.700"
Intake Average Flow: 243 CFM
Exhaust Average Flow: 170 CFM
Intake Seat Material: Ductile Iron
Intake Port Volume: 255cc
Exhaust Port Volume: 106cc
Standard Chamber Volume: 70cc
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: Mast Billet
Rocker Arm Type: LS3 1.7 or Aftermarket
Guide Material: Phosphor Bronze
General
Rocker Stand Type: Mast Billet
Rocker Stands Included: Yes
Rocker Stand Dowels Included: Yes
Uses Stock Rocker Bolts: No
Rocker Bolts Included: No
Rocker Arm Type: LS3 1.7 or Aftermarket
Head Bolt QTY: 6 Bolt Style
Valve Cover Rail Height: + ½ inch
Can use OE Valve Cover: Yes