If you’re a 3rd Gen Cummins owner, you know the 5.9L Common Rail is a well built machine. It’s the engine that put diesel performance on the map. But as turbo technology and fueling capabilities have evolved, we’ve reached a point where bolt-ons can easily out perform what the factory bottom end can handle.

The D&J Precision Machine Street Performance Long Block has entered the chat…

Rated for 1,000 HP and 1,800 lb-ft of torque, this isn’t just a rebuild, it’s a precision engineered foundation designed for the street & racing enthusiasts. Here’s a look at what makes this engine the top tier option for high performance Cummins builds.

1. The Foundation

Most local machine shops can bore a block, but at D&J we take it to a different level. Every Street Performance block is CNC blueprinted. This means the block is machined to perfect tolerance, bored, line-bored, and torque plate honed, to ensure that even under extreme boost, your internal geometry remains accurate.

2. X-Beam Billet Rods

The weak link in a high output 5.9 is often the factory connecting rods. To solve this, we include  X-Beam Stock Length Billet Rods in every Street Performance engine. These are widely considered the strongest billet rods on the market. Whether you’re spooling a big single turbo or a compound setup, these rods are built to handle the cylinder pressure that would turn stock rods into a pretzel.

3. Superior Sealing

When you start pushing towards 1,000 HP, a standard head gasket won’t cut it. To combat head lift, we machine Fire-Ring grooves directly into the cylinder head. Combined with custom ARP 9/16" Head Studs (torqued to a massive 175 ft/lbs), this setup provides the ultimate seal, keeping your coolant and combustion where they belong, even at 80+ PSI of boost.

4. The Stage 1 CNC Head

Horsepower is just air and fuel. To maximize the air side of that  equation, this long block comes equipped with a Stage 1 High-Performance Cylinder Head.

• 5-Axis CNC Porting: Ensures every runner flows identical volume.

• HD Bronze Valve Guides: Superior durability over stock.

• Upgraded Valve Springs: 105# springs to prevent valve float at high RPM.

5. Peace of Mind

Building an engine can be a logistical nightmare. D&J eliminates the stress by shipping these engines fully assembled from the oil pan to the rocker box. They arrive pre-lubed with break-in oil, a filter, and a fresh coat of black paint. What more can you ask for? 

Is it Right for You?

The Street Performance series is specifically designed for the owner who wants a max effort street truck. It’s balanced for drivability but durable enough for a pass at the drag strip or a pull on the dyno.

Note for the Towing Crowd: While this engine is a beast, D&J recommends it for performance based applications. If your truck spends 90% of its life hooked to a 20,000lb trailer, you might want to look at our Heavy Hauler series. But if you want to see four digits on the dyno and still drive to work on Monday, this is your engine!

Learn more about this engine by clicking here.