LS3 Large Bore | Factory Mast | As Cast Port | Cylinder Head - Pair

Limited QTY. Available ---->Download Your Cylinder Head Spec Sheet Here<---- Introducing the Factory Mast "As Cast" Port Cylinder Head. We launched our Factory Mast product line to deliver an economical product line for our customers.  We completely engineered and manufactured our long standing best in class CNC port into an "As Cast" port.  This new process saves a significant amount of time and manufacturing cost, which is savings we pass down to you. You have come to love the "Black Label" Cylinder heads, but now you can get the same quality at a lower price without SACRIFICING performance. Manufactured using permanent mold technology, this casting is simply an amazing surface finish and quality.   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: 28 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: 1.580" Valve Spring Install Height: 1.800" Head Stud Size: .4375" Valve Guide OD: .502" Valve Job Type: As Cast Air Flow & Performance Criteria Intake Max. Flow: 372 CFM @ 1.000" Exhaust Max. Flow: 191 CFM @ 1.000" Intake Average Flow: 287 CFM Exhaust Average Flow: 164 CFM Intake Seat Material: High Chrome Alloy Steel Intake Port Volume: 294cc Exhaust Port Volume: 104cc Standard Chamber Volume: 71cc Port Type: As Cast Materials Cylinder Head Material: A356-T6 Aluminum Intake Valve Seat Material: High Chrome Alloy Steel Exhaust Valve Seat Material: High Chrome Alloy Steel Deck Thickness: .750" Rocker Stand Type: Mast Billet Rocker Arm Type: OE LS7 1.8 or Aftermarket Guide Material: 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: OE LS7 1.8 or Aftermarket Head Bolt QTY: 6 Bolt Style Valve Cover Rail Height: + ½ inch Can use OE Valve Cover: Yes Custom Options Available Head Assembly Custom Chamber Size Chamber Softening 1/2" Head Studs