LS3 Medium Bore | Factory Mast | CNC Ported | Cylinder Head - Single Bare
Expected Ship Date February 2025
We took the Factory Mast LS3- and CNC ported it for even more improvement. Our Factory Mast Cylinder Head starts out with our "as cast" port which we now offer a CNC port for more airflow. This allows for an additional option and price point over our As Cast Port version and our Premium Black Label LS3.
***Download your Cylinder Head Technical Sheet here***
We launched our Factory Mast product line to deliver an economical product line for our customers.
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.
- Bore Size: 4.000 (+)
- Weight: 28.5 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: 1.580"
- Valve Spring Install Height: 1.800"
- Head Stud Size: .4375"
- Valve Guide OD: 0.565"
- Valve Job Type: 5 Angle
Air Flow & Performance Criteria
-
Intake Max. Flow: 358 CFM @ 7.000"
- Exhaust Max. Flow: 230 CFM @ 7.000:
- Intake Average Flow: 236 CFM
- Exhaust Average Flow: 160 CFM
- Intake Seat Material: High Chrome Alloy Steel
- Intake Port Volume: 255cc
- Exhaust Port Volume: 106cc
- Standard Chamber Volume: 70cc
-
Port Type: CNC Ported
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 LS3 1.7 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 LS3 1.7 or Aftermarket
- Head Bolt QTY: 6 Bolt Style
- Valve Cover Rail Height: + ½ inch
- Can use OE Valve Cover: Yes
Custom Options Available
- Custom Chamber Size
- Chamber Softening
- 1/2" Head Studs