DFC Diesel SS661116LMLSOALB Street Series Speed Of Air Long Block (Standard/Auto) | 2011-2016 GM/Chevrolet 2500HD/3500HD 6.6L Duramax LML/LGH

Features:

• 5-year / 160,000 km warranty
• Built with all new OEM components
• Includes ARP or OptiTorque head studs
• Total Seal gapless piston rings
• Precision-machined to factory specifications
• Cylinder heads fully rebuilt and resurfaced
• Upgraded gasket sealing in leak-prone areas
• Woodruff keyed camshaft for reliability
• EDM doweled oil pump gear for durability
• Advanced Rottler machining for accuracy
• Complete top-end gasket kit included
• Pre-set rockers and pushrods to spec

Bring Your Duramax Back To Life With Proven Power

When it is time to breathe new life into your 2011-2016 GM or Chevrolet 2500HD or 3500HD, the DFC Diesel Street Series Speed Of Air Long Block delivers the reliability and performance you can count on every single day. Built with the diesel enthusiast, hard working hauler, and daily driver in mind, this engine is more than just a replacement. It is a full upgrade over stock with improvements made to common problem areas that hold factory engines back. Every Street Series long block comes with all new OEM or equivalent pistons, rings, gaskets, and bearings, so you can feel confident in every mile. The inclusion of ARP or OptiTorque head studs keeps your cylinder heads locked down under heavy loads and high boost, while Total Seal gapless piston rings help maintain compression for lasting power. Whether you are pulling a trailer, heading out for a weekend trip, or just want your truck running at its best, this engine is ready for the task. Backed by one of the most comprehensive 5-year, 160,000 km warranties in North America, it gives you the peace of mind to put your Duramax to work without hesitation.

Engineered With Precision To Outperform Factory Standards

The DFC Diesel SS661116LMLSOALB Street Series Long Block is built from the ground up with performance and durability at its core. Each block is professionally machined and bored for the next oversized piston using advanced Rottler machining equipment, ensuring factory-level precision from the start. The remanufactured cylinder heads are fully refreshed with new valves, guides, seats, and stem seals, then resurfaced and magnafluxed to guarantee proper sealing and reliability. An EDM doweled oil pump gear and woodruff keyed camshaft add extra strength in critical areas, preventing failures that often plague stock engines under stress. Gasket sealing methods have been improved in common leakage points to keep fluids where they belong, even in demanding conditions. Rockers and pushrods are preset to factory specs, allowing for a smooth installation process with fewer adjustments needed. Along with a complete top-end gasket kit included in the package, this long block is ready for a clean, efficient, and dependable install that sets your Duramax up for long term success.

Fits: 2011, 2012, 2013, 2014, 2015, 2016 GM/Chevrolet 2500HD/3500HD 6.6L Duramax LML/LGH

Notes:

• Verify fitment for 2011-2016 LML/LGH applications.
• Speed Of Air piston upgrade is included.
• Long block does not include external accessories.
• Head studs may be ARP or OptiTorque.
• Professional installation by a diesel shop is recommended.
• Freight delivery planning is required before checkout.
• Core return is required using the supplied crate.
• Register the warranty and follow break-in procedures.
• Includes a complete top-end gasket kit for install.
• Rockers and pushrods arrive preset to factory specs.
• Machined for oversize pistons; reuse parts should be inspected.
• Confirm compatibility with your existing fuel and turbo systems.

Street Series vs Tow/Haul vs Tow/Haul HD

• Street Series: Ideal for daily driving, light work, and diesel enthusiasts. Focuses on reliability upgrades over stock, with head stud and sealing improvements.

• Tow/Haul Series: All Street upgrades plus added performance parts for higher load and towing power. Supports builds up to ~700 HP.

• Tow/Haul HD Series: The most robust option. Adds heavy-duty internals like Wagler rods and a balanced rotating assembly for 800+ HP capability.

Standard/Auto vs Standard vs Auto

• Standard/Auto: Compatible with both manual and automatic transmissions. Offers the most flexibility.

• Standard: Built specifically for manual transmission configurations.

• Auto: Built specifically for automatic transmission setups.