Engines and Components› Cylinder Heads and Components

GM

Katech CNC Cylinder Head Porting Service

$499.99

SKU: KAT-M4321

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
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Overview

The Katech KAT-M4321 is a basic CNC cylinder head porting service. It includes precision CNC porting and Katech logo engraving for identification and quality assurance.
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The Katech 241/806/853 Basic CNC Cylinder Head Porting Service (KAT-M4321) offers enhanced engine performance through precision CNC machining of your existing cylinder heads. This service focuses on optimizing the intake and exhaust ports to improve airflow and overall engine efficiency. The process includes precision CNC porting of both intake and exhaust ports, along with a distinctive Katech logo engraving for authenticity and quality assurance. To utilize this service, you will need to remove the cylinder heads from your vehicle, disassemble them to a completely bare condition, and thoroughly wash them. Once prepared, print a copy of your order confirmation and include it in the box with the cylinder heads before shipping them to Katech Engineering at their Clinton Twp., MI facility. Please ensure the cylinder heads are packaged securely with ample bubble wrap within a sturdy box to prevent shipping damage. This service covers only the CNC porting and logo engraving. Assembly, valve work, and any additional machining services are not included and must be added separately if required. Please note that heads arriving with valve seals installed or any oil residue or carbon in the ports will incur a minimum $70 cleaning fee. It is crucial to include your order confirmation with the shipment to prevent processing delays.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandGM
Part NumberKAT-M4321
CategoryEngines and Components
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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