FAQs
What is included in a D&J short block? ▾
A D&J short block includes the engine block, crankshaft, pistons, rods, bearings, and internal rotating assembly components. It does not include the cylinder head, injectors, turbocharger, valve train accessories, or external bolt-on components.
What’s the difference between a short block and a long block? ▾
A short block includes the lower half of the engine. A long block includes the cylinder head, valvetrain components, and additional assembled parts. Short blocks are ideal when your top-end components are still usable.
Is a short block cheaper than a long block? ▾
Yes. Because you’re reusing major upper-engine components, short blocks typically cost significantly less than replacing the entire engine.
Who should buy an Essential short block? ▾
The Essential series is best for stock replacement trucks, daily drivers, fleet trucks, and towing applications looking for dependable OEM-style reliability.
Who should buy a Precision Plus short block? ▾
Precision Plus short blocks are ideal for customers planning future upgrades, heavier towing demands, or wanting additional durability beyond a standard rebuild.
Can I reuse my existing cylinder head? ▾
Yes, if it passes inspection. Many customers pair these with a rebuilt D&J head for maximum reliability.
What causes a Cummins short block failure? ▾
Common causes include piston damage, excessive EGTs, injector failure, bearing wear, oil contamination, overheating, and poor tuning.
Are these good for towing? ▾
Absolutely. Many customers use these in heavy towing applications where reliability matters most.
Can I add performance upgrades later? ▾
Yes. Many customers install a short block now and upgrade turbochargers, injectors, or fuel systems later.
Why choose D&J over a local machine shop rebuild? ▾
D&J specializes in Cummins engines every day. Their machining processes, tolerances, and diesel-specific experience help eliminate many common rebuild mistakes.