[{"id":429064716501,"handle":"2024-tax-season-sale","updated_at":"2024-04-24T15:20:16-05:00","published_at":"2024-02-07T11:02:58-06:00","sort_order":"best-selling","template_suffix":"","published_scope":"global","title":"2024 \"Tax Season\" Sale","body_html":"00% Off Factory Mast Cylinder Heads PLUS Pre-sale Shopping Opportunity"},{"id":347630918,"handle":"best-selling-products","title":"Best Selling Products","updated_at":"2024-04-30T15:37:26-05:00","body_html":null,"published_at":"2016-10-02T12:22:59-05:00","sort_order":"best-selling","template_suffix":null,"disjunctive":true,"rules":[{"column":"title","relation":"contains","condition":"Best Selling"},{"column":"title","relation":"not_contains","condition":"Best Selling"}],"published_scope":"global"},{"id":420292559061,"handle":"black-friday-sale-factory-mast-heads","updated_at":"2024-04-24T15:20:16-05:00","published_at":"2023-11-14T14:51:46-06:00","sort_order":"best-selling","template_suffix":"collection","published_scope":"global","title":"Black Friday Sale","body_html":"\u003cdiv style=\"text-align: center;\"\u003e45% Off Factory Mast Heads (does not include heads with titanium valves)\u003c\/div\u003e"},{"id":242176032967,"handle":"factory-mast-ls-cylinder-heads","updated_at":"2024-04-24T15:20:16-05:00","published_at":"2021-01-19T13:13:30-06:00","sort_order":"manual","template_suffix":"","published_scope":"global","title":"Factory Mast - LS Cylinder Heads","body_html":""},{"id":401051746517,"handle":"ls-cylinder-head","updated_at":"2024-04-25T13:55:13-05:00","published_at":"2022-01-19T14:28:35-06:00","sort_order":"manual","template_suffix":"","published_scope":"global","title":"LS Cylinder Heads","body_html":""},{"id":416547700949,"handle":"ls3-cylinder-heads","updated_at":"2024-04-25T13:55:13-05:00","published_at":"2023-04-10T17:29:10-05:00","sort_order":"best-selling","template_suffix":"","published_scope":"global","title":"LS3 Cylinder Heads","body_html":""},{"id":170383245409,"handle":"all-cylinder-heads","updated_at":"2024-04-25T13:55:13-05:00","published_at":"2020-09-06T12:55:14-05:00","sort_order":"manual","template_suffix":"collection","published_scope":"global","title":"Products - All Cylinder Heads","body_html":""}]
["As Cast","cylinder heads","Factory Mast","Hydraulic","LS","ls3","medium bore","W\/ Stainless Valves","W\/ Titanium Valves","W\/ Valves"]
Skip to content
Home
›
LS3 Cylinder Heads
›
LS3 Medium Bore | Factory Mast | CNC Ported | Cylinder Head - Pair w/ Valves
LS3 Medium Bore | Factory Mast | CNC Ported | Cylinder Head - Pair w/ Valves
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. Dimensional Specs
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: .565"
Valve Job Type: 5 Angle
Air Flow & Performance Criteria
Intake Max. Flow:
Exhaust Max. Flow: Intake Average Flow:
Exhaust Average Flow:
Intake Seat Material: High Chrome Alloy Steel
Intake Port Volume:
Exhaust Port Volume:
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 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
