DDP Stage 1 Injectors | 1989-1993 5.9L 12V Cummins 275HP

Q: Do I need the copper sleeve adapter for a non-intercooled engine?

No. The 1.5mm copper washer included with these injectors has been used in non-intercooled heads for over 20 years without issues. It positions the nozzle closer to the piston for a cleaner burn than the sleeve adapter. If you still want the adapter, it is Cummins PN 3919358, but it is not recommended by Dynomite.

89-93 Dodge Ram 5.9L Cummins Dynomite Diesel 50HP STG1 Injectors

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Dynomite Diesel Stage 1 Injector Set - 1989-1993 5.9L 12V Cummins

This product qualifies for free shipping!

$619.88

$688.75

Part Number: DDP8993-1
Est. Ship Time: Usually Ships from MFG In 1-3 Days

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Not for Sale in California or Colorado
This injector set cannot be sold or shipped to CA or CO addresses. Verify your shipping address is eligible before ordering.

Upgraded Fuel Pin Required to See Gains
These injectors work with the VE rotary injection pump. Without an upgraded fuel pin installed, little to no power gain will result from the injector upgrade. Dynomite Diesel's upgraded fuel pin is sold separately - see the DDP PIN.

The DDP8993-1 is a Stage 1 matched injector set for the 1989-1993 Dodge Ram 5.9L 12-valve Cummins. Sold brand new with no core required, these injectors support up to 275 RWHP with proper supporting modifications and feature Dynomite Diesel's patented Pilot Hole Technology for reduced smoke and improved spool behavior. This is a performance upgrade, not a stock-spec replacement.

Is This the Right Injector Set for Your Build?

Buy this if... your truck is a 1989-1993 first-gen 5.9L 12-valve Cummins, you have or will install the upgraded fuel pin, and your build targets up to 275 RWHP.
Buy this if... you want the smoke control and spool benefits of pilot hole technology in a brand new matched set with no core charge.
Do not choose this if... your goal is a pure stock-spec restoration - these are performance-spec injectors, not OEM replacements.
Do not choose this if... the VE pump fuel pin upgrade is not in your build plan - without it, these injectors will not deliver meaningful gains on this platform.
Verify before ordering... your truck is a true 1989-1993 first-gen 12-valve application and your fuel pin upgrade is confirmed or planned before installation. Eligible shipping address required.

Why the Fuel Pin Comes Before the Injectors

On the 1989-1993 first-gen VE pump platform, the injectors are only half the equation.

The VE rotary injection pump uses a factory fuel pin that limits how much fuel the pump can deliver regardless of injector size. Installing upgraded injectors without first addressing the fuel pin means the pump cannot take advantage of what the injectors can flow - and gains will be minimal to none. The DDP PIN fuel pin upgrade is sold separately and is not optional on this platform.

Address the fuel pin first, then install injectors. In that order, these injectors deliver exactly what they are rated for.

Non-Intercooled Engine Fitment - Skip the Copper Sleeve

Non-intercooled first-gen engines have a 9mm diameter injector nozzle bore in the cylinder head. These injectors use a 7mm diameter nozzle. Some manufacturers supply a copper sleeve adapter to bridge the size difference, but Dynomite does not recommend it and it is not needed.

The 1.5mm copper washer included with these injectors has been used with non-intercooled heads for over 20 years without issues. It is 0.5mm thinner than the sleeve adapter, which positions the nozzle tip closer to the piston for a cleaner burn, improved fuel economy, and better power output. If you still prefer the adapter, it is available as Cummins PN 3919358 - but Dynomite recommends against it.

What Pilot Hole Technology Actually Does

These injectors use a 5-hole + 2 pilot hole nozzle. The two pilot holes allow fuel to enter the combustion chamber gradually instead of all at once. The practical result is better spool behavior and reduced smoke compared to standard nozzle designs at this power level - without needing to sacrifice one for the other. This is Dynomite Diesel's patented technology and a meaningful real-world differentiator at 275 RWHP.

Injector Specs

Application: 1989-1993 Dodge Ram 5.9L 12-valve Cummins
Condition: Brand new matched set
Rated HP: up to 275 RWHP with proper supporting modifications
Nozzle style: SAC nozzle
Hole count and diameter: 5x11, 44 LPM, 155 degrees
Pilot holes: 2 pilots at 0.005 inches (patented)
Pop pressure: 245 BAR
Copper washer: 1.5mm included
No core required

Avoid These Common Mistakes

Installing without the upgraded fuel pin. The most common missed step on first-gen VE pump builds. Without the DDP PIN, the pump cannot deliver what these injectors can flow. Order it alongside this set if you have not already done it.
Using the copper sleeve adapter on non-intercooled engines. It is not needed and Dynomite does not recommend it. The included 1.5mm copper washer is the better choice - thinner, and it positions the nozzle closer to the piston for a cleaner burn.
Ordering for a 1994-1998 12-valve truck. These injectors are specific to 1989-1993 first-gen applications. The 1994-1998 12-valve uses a different injection system. Verify your exact model year before ordering.
Ordering as a stock-spec replacement. These are performance-spec injectors with upgraded nozzle geometry and pop pressure. If the goal is factory-spec restoration, a stock-spec set is the correct choice.

Before You Order

Truck is a 1989-1993 Dodge Ram 5.9L 12-valve Cummins
VE pump fuel pin upgrade confirmed in the build plan
Power target at or under 275 RWHP with supporting modifications
Shipping address is outside restricted states

All four confirmed? The DDP8993-1 is the correct Stage 1 injector set for your first-gen 12-valve Cummins build.

Frequently Asked Questions

Click or tap a question below to expand the answer.

Do I need to upgrade the fuel pin when installing these injectors?

Yes. The 1989-1993 5.9L 12-valve uses a VE rotary injection pump with a factory fuel pin that limits fuel delivery. Without upgrading it first, these injectors will deliver little to no power gain. The upgraded fuel pin is sold separately - see the DDP PIN. This is the foundational support modification for this injector set on this platform.

What does pilot hole technology do and why does it matter?

The 5-hole + 2 pilot nozzle allows fuel to enter the combustion chamber gradually rather than all at once. The two small pilot holes reduce smoke at startup and improve spool time - without the excessive smoke that larger injectors can produce at partial load. This is Dynomite Diesel's patented technology and a practical differentiator at this power level compared to standard multi-hole designs.

Do I need the copper sleeve adapter for a non-intercooled engine?

No. Non-intercooled engines have a 9mm bore and these injectors use a 7mm nozzle. Some manufacturers supply a copper sleeve to bridge the difference, but Dynomite does not recommend it. The 1.5mm copper washer included with these injectors has been used in non-intercooled heads for over 20 years without issues. It is thinner than the sleeve and positions the nozzle closer to the piston for a cleaner burn. If you still want the adapter, it is Cummins PN 3919358 - but it is not recommended or required.

Is a core return required for this injector set?

No. These injectors are sold as a brand new matched set with no core charge and no core return required.

Will these injectors fit a 1994-1998 12-valve Cummins?

No. These injectors are specific to the 1989-1993 first-gen 12-valve 5.9L Cummins. The 1994-1998 12-valve trucks use a different injection system and require a different injector set. Verify your exact model year before ordering.

What does matched set mean and why does it matter?

A matched set means all six injectors are flow-tested and matched to deliver consistent fuel quantities across every cylinder. This reduces cylinder-to-cylinder variation for even power distribution, better smoke control, and a balanced engine. These are sold as a matched set from new production, not individually sourced units mixed together.