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Cummins ISB 24-Valve (5.9 L) Engines for Sale

Cummins ISB 24-Valve (5.9 L) Engines For Sale

First unveiled in 1998, the Cummins ISB 24-Valve replaced its 12-valve 6BT predecessor and brought with it a greater level of power and efficiency. This version of the 5.9L Cummins received a few injection system upgrades, which increased power output while simultaneously reducing emissions. The ISB 5.9L also introduced a 24-valve cylinder head, electronic control, a more efficient oil pump, and an improved camshaft (along with longer pushrods).

The Cummins ISB 24-Valve 5.9L remains a popular engine for light-duty truck applications, and Big Bear Engine Company is pleased to provide Cummins ISB 24-Valve replacement long blocks for Dodge Ram 2500/3500 truck owners.

5.9L ISB 24-Valve Long Blocks

Red 5.9 Cummins ISB 24 Valve Engine for Sale on Top of a Blue Plastic

If you have a Cummins 5.9L ISB 24-Valve with ancillary parts that still have plenty of life left to give but whose internal hard parts are in need of attention, then our long blocks are a sound, feasible solution. They allow you to start with a fresh block, cylinder head, and crankshaft without having to spend extra on components you don't need. This is a highly cost-effective option and comes with only a minor amount of extra labor to dress the engine out using the retained components from your old engine.

Remanufactured Cummins ISB 24-Valve 5.9L Component Builds

Our component builds for the 5.9L 24-Valve engines consist of a combination of new and remanufactured parts. Usually the block, crankshaft and camshaft are remanufactured back to OEM specs. Depending on the availability of the parts, the block, cam, crank and cylinder head can be brand new castings. Ancillary parts such as the bearings, piston, rings, gaskets, and seals are sourced from a combination of OEM and aftermarket parts suppliers. As a general guide, a component build is roughly 90 percent OEM parts, 10 percent aftermarket components.

Our Dodge ISB 24-Valve 5.9L engines generally fit a 2003-2007 replacement year Ram 2500 or 3500. However, the long block is configured for the 1998-2002 VP44 injection pump. The ISB 5.9 L blocks, camshafts, crankshafts and cylinder heads were interchanged throughout the years. If you have a common-rail fuel pump (2003-2007 engine), check with our sales staff to see if our long block (minus the front cover and gear housing) will work as a suitable replacement.

Big Bear 5.9L long blocks fit CM550 and work best with the following CPLs:

  • CPL 2683
  • CPL 8164
  • CPL 2684
  • CPL 2685
  • CPL 2617
  • CPL 2686

Big Bear Long Block Assemblies Include:

  • Block
  • Cylinder Head
  • Camshaft
  • Camshaft Gear
  • Followers and Lifters
  • Pistons
  • Piston Rings
  • Gaskets
  • Bearings
  • Plugs and Bolts
  • Push rods
  • Connecting Rods
  • Front Cover
  • Timed Front Gear Train Group
  • Crankshaft
  • Oil Pump
  • Oil Cooler
  • Freeze Plugs and Block Plugs
  • Front Rear and Main Seal
  • Valve Cover
  • Oil Pickup Tube

Cummins 5.9L ISB 24-Valve Engine Applications

Side View of a Red 5.9 Cummins ISB 24 Valve Engine for Sale on Top of a Blue Plastic

By far the most common application for Cummins ISB 24-Valve engines is their use in light-duty trucks. Specifically, these engines were used in Dodge Ram pickup trucks starting in 1998 (model year 1998.5), when they replaced the previous 6BT models.

Over the course of the next nine years, the Cummins ISB 24-Valve 5.9L engine received a number of upgrades, which made it an even better fit for pickup truck applications. In 2003, a Bosch high-pressure common rail injection system added power and torque while also cutting down on engine noise, which made the Cummins ISB 24-Valve one of the most popular engines on the market.

Though light-duty trucks eventually transitioned to utilizing ISB 6.7 L engines in 2007 (model year 2007.5), the ISB 24-Valve remains a popular option for those with older trucks, or who are less concerned about emissions.

Beyond Dodge Ram applications, you'll find the Cummins ISB 24-Valve engine in use in step vans, commercial delivery vehicles, and similar applications. Cummins' ISB engine is a quality unit that has a wide range of potential applications, and it’s not hard to see why it was ranked as one of Ward's "10 Best Engines" in 2004, or why many still feel that it deserves such an accolade.

Cummins ISB 24-Valve (5.9L) Specs

Engine Data

ConfigurationInline-six Cylinder, Four-Stroke
Displacement359 ci, 5.9L
Bore x Stroke4.02 inches x 4.72 inches
Cylinder Head MaterialCast Iron
Engine Block MaterialCast Iron
Firing Order1-5-3-6-2-4
Compression Ratio16.3:1, 17.2:1 for 2001-2002 High Output Models
AspirationSingle turbocharger, air-to-air intercooler
ValvetrainOHV, 4 valves per cylinder, solid lifter camshaft
WeightApproximately 1,150 lbs
Oil Capacity12 Quarts
Governor Speed3,200 rpm
Horsepower235 hp to 245 hp (1998.5-2002), 305 hp to 325 hp (2003-2007)
Torque460 lb-ft to 505 lb-ft (1998.5-2002), 555 lb-ft to 610 lb-ft (2003-2007)
Engine Dimensions40 inch (L) x 24.9 inches (W) x 37.9 inches (H)


Give us a call today at 844-340-4114 for immediate sales and support for the Cummins 4BT, Cummins 6BT, 6CT, ISC, 855, QSB 4.5 L or CAT 3306. If you have any questions, check out our FAQ Page. We are always ready to help or just listen to your crazy off-roading adventures!

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