DFC Diesel SS660104LB7SOALB Street Series Speed Of Air Long Block (Standard/Auto) | 2001-2004 GM/Chevrolet 2500HD/3500HD 6.6L Duramax LB7

Features:

• 5-year, 160,000 km industry-best warranty
• Built for 2001–2004 Duramax LB7 trucks
• Ideal for daily driving and work trucks
• Includes remanufactured cylinder heads
• ARP or OptiTorque head studs installed
• Total Seal gapless piston rings standard
• All new OEM-grade internal components
• Professionally machined and bored block
• Keyed camshaft for better timing reliability
• Includes complete top-end gasket kit
• EDM doweled oil pump gear for strength
• Improved sealing in high-failure areas

Built For Durability Without Giving Up Driveability

If you’re rebuilding a 2001–2004 Duramax 2500HD or 3500HD, the DFC Diesel Street Series Long Block is a rock-solid upgrade that doesn’t just replace your worn engine, it improves on it. Designed with work trucks, daily drivers, and diesel enthusiasts in mind, this remanufactured 6.6L LB7 long block gives you the reliability of a factory build with smart upgrades where it counts. Backed by a 5-year, 160,000 km warranty, it’s clear DFC stands behind their craftsmanship. This Street Series setup includes ARP or OptiTorque head studs for enhanced clamping force, giving you better protection against common LB7 issues like head gasket failures. What makes this package even more appealing is the fact that every internal component is brand new, from pistons and rings to valves and gaskets, so you’re not gambling on reused parts. The included top-end gasket kit and preset valvetrain make installation smoother and faster, cutting down on shop time and headaches. Whether you're hauling loads, commuting daily, or just want a reliable diesel that can take a beating and keep going, this long block delivers performance and peace of mind in one package.

Precision Remanufacturing Meets Real World Diesel Demands

At the core of the DFC SS660104LB7SOALB Street Series engine is a fully remanufactured long block, machined to exacting standards using advanced Rottler equipment for consistent tolerances and long-term reliability. The block is bored to fit next oversized pistons, which are paired with Total Seal gapless rings to improve combustion efficiency and reduce blow-by. DFC’s attention to detail continues with their EDM doweled oil pump gear and woodruff-keyed camshaft, both designed to enhance engine stability and protect against long-term wear. Every cylinder head is resurfaced and magnafluxed, then fitted with all new seats, guides, valves, and seals to ensure like-new performance. This build includes a full top-end gasket kit to complete your install, along with rockers and pushrods already set to factory spec. By using all-new OEM or equivalent components throughout the engine, DFC eliminates the guesswork that often comes with other rebuild options. The result is a long block that meets or exceeds original specs while being tailored to handle the stress of daily use, towing, and moderate performance upgrades with ease.

Fits: 2001, 2002, 2003, 2004 GM/Chevrolet 2500HD/3500HD 6.6L Duramax LB7

Notes:

• Designed for 2001–2004 GM/Chevy 2500HD and 3500HD trucks with 6.6L LB7 Duramax engines
• Street Series is intended for daily driving and light towing applications
• Includes remanufactured long block with new pistons, rings, gaskets, bearings, and cylinder heads
• Cylinder heads are resurfaced, magnafluxed, and fitted with new valves, guides, and seals
• Comes with ARP or OptiTorque head studs depending on availability
• Engine block is bored for use with next oversized pistons
• Top-end gasket kit included to complete installation
• Valvetrain components come pre-set to factory specifications
• All engines are machined in-house using advanced Rottler equipment
• Backed by a 5-year or 160,000 km limited warranty
• Not a drop-in engine – installation must follow standard procedures and proper break-in
• Core charge and return policies may apply depending on supplier or distributor

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.