[{"id":170473980001,"handle":"all-products","updated_at":"2025-10-25T06:00:48-05:00","published_at":"2020-09-09T18:55:52-05:00","sort_order":"best-selling","template_suffix":"pf-e03b4526","published_scope":"global","title":"All The Parts","body_html":""},{"id":347630918,"handle":"best-selling-products","title":"Best Selling Products","updated_at":"2025-10-29T06:00:29-05:00","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":239859925191,"handle":"black-label-ls3-heads","updated_at":"2025-10-16T06:00:39-05:00","published_at":"2020-12-23T13:14:09-06:00","sort_order":"manual","template_suffix":"","published_scope":"global","title":"Black Label - LS3 Heads","body_html":""},{"id":404018266325,"handle":"black-label-cylinder-heads","updated_at":"2025-10-16T06:00:39-05:00","published_at":"2022-03-14T10:16:40-05:00","sort_order":"manual","template_suffix":"","published_scope":"global","title":"Black Label Cylinder Heads","body_html":"\u003cdiv style=\"text-align: center;\"\u003eLooking for something more specific ?\u003c\/div\u003e\n\u003cdiv style=\"text-align: center;\"\u003e\u003ca href=\"https:\/\/www.mastmotorsports.com\/collections\/black-label-cathedral-heads\"\u003eCathedral Port Heads\u003c\/a\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align: center;\"\u003e\u003ca href=\"https:\/\/www.mastmotorsports.com\/collections\/black-label-ls3-heads\"\u003eLS3 Heads\u003c\/a\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align: center;\"\u003e\u003ca href=\"https:\/\/www.mastmotorsports.com\/collections\/black-label-ls7-heads\"\u003eLS7 Heads\u003c\/a\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align: center;\"\u003e\u003ca href=\"https:\/\/www.mastmotorsports.com\/collections\/black-label-lt-di-cylinder-heads\"\u003eLT Heads\u003c\/a\u003e\u003c\/div\u003e\n\u003ch5\u003e\u003c\/h5\u003e"},{"id":401051746517,"handle":"ls-cylinder-head","updated_at":"2025-10-29T06:00:29-05:00","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":"2025-10-29T06:00:29-05:00","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":"2025-10-29T06:00:29-05:00","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":""}]
["4.125\"","Black Label","CNC","cylinder heads","Hydraulic","Jesel","jesel pattern","large bore","LS","LS3","W\/ Stainless Valves","W\/ Titanium Valves","W\/ Valves"]
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LS3 295cc 4.125" (+) Bore - Pair Black Label CNC Cylinder Heads - Stainless Steel or Titanium Valves - Jesel Pattern
Stainless Steel Valves
Titanium Intake & Stainless Steel Exhaust
Description
Description
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: 4.125" (+)
Weight: 27.5 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: 1.65"
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: 397 CFM @ 0.700"
Exhaust Max. Flow: 248 CFM @ 0.700"
Intake Average Flow: 254 CFM
Exhaust Average Flow: 176 CFM
Intake Seat Material: Ductile Iron
Intake Port Volume: 295cc
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: Jesel
Rocker Arm Type: Jesel
Guide Material: Phosphor Bronze
General
Rocker Stand Type: Jesel
Rocker Stands Included: No
Rocker Stand Dowels Included: No
Uses Stock Rocker Bolts: No
Rocker Bolts Included: No
Rocker Arm Type: Jesel
Head Bolt QTY: 6 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
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