DFC Diesel TH599497SOALB Tow/Haul Series Speed of Air Long Block (STD/Auto) | 1994-1997 Dodge RAM 5.9L Cummins 12V

Features:

• Fits 1994–1997 5.9L Cummins 12V engines
• Built for towing and performance up to 700 HP
• Includes ARP or OptiTorque head studs
• Cometic MLS multi-layer steel head gasket
• Stage 3 camshaft for increased performance
• 60lb heavy-duty valve springs (1994–1998)
• Manton HD push rods for added durability
• Ceramic coated piston crowns for heat resistance
• Dry film coated piston skirts for wear protection
• Gapless Total Seal piston rings included
• Professionally machined block and head assembly
• Backed by 5-year / 160,000 km warranty

Built for the Load, Tuned for the Long Haul

If your 1994–1997 5.9L Cummins 12-valve is more than just a weekend toy—if it’s hooked to a trailer, moving heavy loads, or tuned for serious grunt—the DFC Diesel Tow/Haul Series Speed of Air Long Block (STD/Auto) is the kind of engine you want under the hood. This isn’t your basic reman. It’s a purpose-built long block that combines the reliability of factory-fit machining with performance-focused upgrades that are made for work. Whether you're pulling a fifth wheel through the mountains or stacking up highway miles with a loaded trailer behind you, this engine is designed to keep the temps down, the power up, and the reliability right where you need it.

Heavy-Duty Components with Proven Performance

What separates this build from the standard Street Series is a list of serious enhancements made specifically for high-stress use. Inside, you’ll find ceramic-coated piston crowns and dry film-coated skirts—features that improve heat resistance and reduce friction where it matters most. The stage 3 camshaft and Manton heavy-duty pushrods pair with upgraded valve springs (60lb for 12-valve models like yours) to handle higher RPM and boost pressure without flinching. It’s all clamped together with ARP or OptiTorque head studs and sealed with a Cometic MLS gasket set. DFC also includes Total Seal gapless rings for better compression and longevity. Everything is machined on advanced Rottler equipment and backed by a 5-year, 160,000 km (100,000 mi) warranty, so you’re covered from the first startup to the last tow. For the Cummins owner who expects more than stock—this is the long block that’s ready to work as hard as you do.

Fits: 1994, 1995, 1996, 1997 Dodge RAM 5.9L Cummins 12V

Product Image Note: Some images may be representative.