2004.5-2005 LLY Stock New Duramax Heads - Industrial Injection

Industrial Injection 2004.5-2005 LLY Duramax NEW Premium Stock Plus Cylinder Heads (RH & LH Set)

Name: Industrial Injection 2004.5-2005 LLY Duramax NEW Premium Stock Plus Cylinder Heads (RH & LH Set)
Brand: Industrial Injection
SKU: PDM-LLYSHN
Price: 2399.95 USD
Availability: InStock

Industrial Injection

SKU: PDM-LLYSHN

Price

$2,399⁹⁵

$0⁰⁰ $2,399⁹⁵

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Free Ground shipping (Over $200*)

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2004.5-2005 LLY Duramax Premium Stock Plus New Cylinder Heads (RH & LH Set)

Restore factory performance and reliability to your 2004.5–2005 LLY Duramax 6.6L with these brand-new Premium Stock Plus cylinder heads. Designed as a direct replacement for factory heads, these new castings eliminate the uncertainty associated with remanufactured cores while delivering the durability, airflow, and performance required for stock and mild performance applications.

Each cylinder head is precision machined and assembled using premium components to ensure proper sealing, valvetrain stability, and long service life. Whether you're replacing damaged cylinder heads or building a fresh engine, these Premium Stock Plus heads provide a dependable foundation for your Duramax.

Key Features

Brand-new LLY Duramax cylinder head castings
Precision machined and assembled
Diamond honed valve guides
Unshrouded valves for improved airflow
High-strength, heat-treated iron-based valve guides
Premium nickel-based, non-magnetic valve seat inserts
Multi-angle valve job
New valve springs installed
Assembled and ready for installation
Direct replacement for factory cylinder heads
Ideal for stock replacement or mild performance builds

Premium Stock Plus Construction

Built from all-new castings, these Premium Stock Plus cylinder heads are engineered to provide exceptional reliability and performance. Each head undergoes precision machining and assembly processes to ensure consistent quality, proper sealing, and optimal airflow.

By starting with brand-new castings, these heads eliminate concerns associated with used cores, cracks, repairs, or previous heat cycles, providing a fresh foundation for long-term engine durability.

What's Included

Left and right new LLY cylinder heads
Fully assembled and ready to install

Not Included

Gaskets
Head bolts
Injectors
Installation hardware

Vehicle Fitment

2004.5–2005 GM Duramax LLY 6.6L

Chevrolet Silverado 2500HD
Chevrolet Silverado 3500HD
GMC Sierra 2500HD
GMC Sierra 3500HD

Why Choose These New LLY Cylinder Heads?

Brand-new castings with no core history
OE-style fit, function, and performance
Premium valvetrain and machining upgrades
Ideal for engine rebuilds and cylinder head replacement
Built for long-term durability and dependable operation

Core Return Information

Sold as a matched left and right pair.

To receive full core credit, a good, reusable pair of LLY cylinder heads must be returned. Cores must be free of cracks, excessive warping, or severe damage. Core returns are required within 90 days of purchase.

Shipping information

Free economy ground shipping on most orders over $200. This includes lower 48 United States only. Excludes products that must ship freight.

Core Return Info

Read Carefully!

When you purchase a product from our website that has a core requirement, you have two options:

1. You choose to pay the core charge and we will ship the product right away, then once we receive the cores you will be refunded the core charge if your cores pass our inspection qualifications. This is the preferred choice and has the least delays.

2. You choose to send in your cores before we ship the product that was purchased. This choice has the risk of delayed shipment of your purchased product and our inventory is not guaranteed by the time we receive your cores. You will need to follow all of the instructions below as quickly as possible so that you can get your purchased product and we can receive the cores. When you choose this option you acknowledge that by the time we receive your cores, our inventory could have change and there could be a delay in your shipment.

Please return all cores to:

Industrial Injection Core Returns
2858 South 300 West
Salt Lake City, Utah 84115

INCLUDE RA# THAT WAS ISSUED AT TIME OF PURCHASE! If RA # is lost, please call Customer Service at (800) 955-0476. Have your original invoice at time of phone call to give all appropriate information for return.

Core return freight is the responsibility of the customer

FULL CREDIT WILL BE GIVEN WHEN:

In order to receive full core credit, your core(s) must be returned within 90 days from receipt of order. It must be as is “off the engine.” Full core credit will be given if core meets acceptance criteria. Cores that are damaged during shipment to Industrial Injection are the responsibility of the customer and their shipping company.

½ CORE CHARGE CREDIT WILL BE GIVEN WHEN:

Slightly damaged housing or camshaft
Missing parts such as FCA

No Core Credit issued when:

Core is seized or hydraulic head is cracked
Excessive damage ( Heavy use of Bio-diesel and rust are common causes for unacceptable core)
Core is fire damaged
Core is returned after 90 days/3months

Please do the following when returning a core:

Make sure you have removed all fittings from your old unit
Drain all fuel and oil from unit
Package cores so that fuel and oil does not escape from the package

NOTE: packages that have fuel or oil residue on the outside of the box during shipping will not be delivered by UPS or the postal service which will cause delays.

Please re-use boxes and bags that parts were shipped in originally. These boxes are UPS approved to reduce damage while being handled in freight.
All shipping charges are the responsibility of the customer
Please write on the box “Core Return” and have RA # clearly written on the outside of box
Include copy of original invoice and RGA inside box

PLEASE RETAIN RA#, INVOICE # AND TRACKING NUMBER UNTIL CREDIT IS RECEIVED BY YOU. We do not research by customer name, only invoice # or RA #.