DFC Diesel TH6607510LMMSOALBHD Tow Haul HD Series Speed Of Air Long Block (Standard/Auto) | 2007.5-2010 GM/Chevrolet 2500HD/3500HD 6.6L Duramax LMM

Features:

• Rated for up to 900 horsepower output
• Wagler forged connecting rods included
• Alternate firing Wager Stage 1 camshaft
• Callies Compstar crankshaft for added strength
• Includes HD flexplate for drivetrain stability
• ATI dampener reduces harmonic vibration
• Balanced rotating assembly for smoother operation
• Includes all Tow/Haul and Street Series upgrades
• Built for high-torque towing applications
• Total Seal gapless piston rings included
• Backed by 5-year, 160,000 km warranty
• Ideal for trucks running 500–750 HP daily

Push Power Further Without Sacrificing Daily Driveability

If you’re chasing big horsepower but still want to tow heavy and drive your truck every day, the DFC Tow/Haul HD Series Long Block gives you the best of both worlds. This engine is designed for Duramax LMM owners running between 500 and 750 horsepower on the regular, with the capability to reach up to 900 at the flywheel. It’s the kind of build that’s meant for guys who pull serious weight during the week and still want to have some fun on the weekends. DFC took their proven Street and Tow/Haul Series and beefed it up even more with serious internal upgrades like Wagler forged rods, a Wager Stage 1 alternate firing camshaft, and a fully balanced rotating assembly. The included Callies Compstar crankshaft, ATI damper, and HD flexplate all work together to give this engine the strength and smoothness you need when you’re pushing big torque under load. This isn’t just about horsepower, it’s about building a truck that works hard and stays together doing it. And with DFC’s 5-year, 160,000-kilometer warranty, you’ve got peace of mind to match the performance.

Built With Forged Strength And Precision Balance

The DFC Diesel TH6607510LMMSOALBHD Tow/Haul HD Series Long Block is engineered to handle aggressive power and high-load towing without compromising long-term reliability. Designed for 2007.5 to 2010 GM and Chevy trucks running the 6.6L Duramax LMM, this build includes all the foundational upgrades of the Street and Tow/Haul Series along with several critical reinforcements. Wagler forged connecting rods deliver increased strength under high cylinder pressures, while the Wager Stage 1 alternate firing camshaft helps improve exhaust scavenging and smooth engine operation. A Callies Compstar crankshaft, paired with a balanced rotating assembly, minimizes vibration and enhances overall longevity. The HD flexplate and ATI dampener work together to reduce stress on the drivetrain, particularly when towing heavy loads or operating under consistent boost. Like all DFC long blocks, the heads are fully rebuilt, components are preset to spec, and the machining process ensures precision fitment. This is a serious performance build that blends real-world usability with competition-ready hardware.

Fits: 2007.5, 2008, 2009, 2010 GM/Chevrolet 2500HD/3500HD 6.6L Duramax LMM

Notes:

• Designed for 2007.5–2010 6.6L Duramax LMM engines
• Fits GM/Chevy 2500HD and 3500HD trucks with standard or automatic transmissions
• Engine is a long block configuration and not a complete drop-in assembly
• Built for trucks regularly running 500–750 horsepower
• Capable of supporting up to 900 horsepower at the flywheel
• Includes all upgrades from the Street and Tow/Haul Series
• Comes with heavy-duty internal components for high-stress use
• Fuel system, turbocharger, electronics, and accessories are not included
• Crankshaft, flexplate, and dampener are upgraded for strength and balance
• All valvetrain components come pre-set to factory specs for easier install
• Professional installation is strongly recommended for best performance
• Backed by a 5-year or 160,000 kilometer limited warranty
• Core return may be required to complete the transaction

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.