The 6.7 Cummins VGT has a well-documented failure cycle. Vanes stick, actuators throw P003A and P0299 codes, bearings wear out on hard-working trucks, and owners end up facing a $2,500 to $4,000 repair bill for the same turbo architecture that failed in the first place.
That moment, when the factory VGT fails, and you’re deciding whether to replace it with the same unit or finally upgrade, is exactly what drives most buyers to start researching a 6.7 Cummins turbo upgrade kit.
Turbo Diesel of Oklahoma stocks turbo upgrade kits, rebuilt units, and exchange turbos for 6.7 Cummins-powered Ram 2500/3500 trucks and commercial chassis. The team has been sourcing diesel components since 1988, with over 100 years of combined experience across the parts desk, and parts are in stock and ready to ship. If you’re on a deadline, that availability matters.
In this guide, you’ll find a clear breakdown of every realistic upgrade path for the 6.7 Cummins, from drop-in VGT replacements to compound turbo systems. You’ll also get the fitment and spec checks that prevent costly mistakes, a comparison of OEM, rebuilt, exchange, and aftermarket options, and the information you need to get a quote fast and get the truck moving.
What Buyers Need to Know First
The 6.7 Cummins uses a Holset variable-geometry turbocharger across all model years, but the specific unit depends on the truck’s year and platform.
Truck And Engine Applications
Three distinct factory VGT configurations cover the full 2007.5 through 2024 production run:
- 2007.5 to 2012 Ram 6.7L: Holset HE351VE VGT
- 2013 to 2018 Ram 6.7L: Holset HE300VG VGT
- 2019 to 2024 Ram 6.7L: Holset HE300VG VGT, 5th gen platform with a proprietary lower-mount flange
The 5th gen (2019 to 2024) uses a different exhaust flange than 4th gen trucks. This matters when selecting a swap kit or compound system. Commercial chassis applications on the 4500 and 5500 series can have additional clearance and mounting differences that affect which kit fits without modification.
Knowing your exact year, platform (Ram vs. commercial chassis), and whether the truck has been deleted determines which upgrade path is physically possible.
Why Owners Upgrade the Factory Turbo
Most 6.7 Cummins turbo upgrades are triggered by one of a handful of recurring failure patterns. Common symptoms that push owners toward an upgrade rather than a straight OEM replacement include:
- Sticking vanes from soot accumulation causing sluggish throttle response or limp mode
- Actuator failure with codes P003A, P2262, P00AF, or P0299
- Excessive shaft play or oil consumption pointing to bearing wear
- EGTs too high while towing, even on a functioning factory turbo
- A desire for more power headroom without chasing repeated VGT failures
If the truck is already down for a turbo replacement, the incremental cost of upgrading rather than replacing is often worth the long-term reliability gains.
OEM, Aftermarket, Rebuilt, And Exchange Paths
OEM replacement means buying a factory-spec HE351VE or HE300VG, which resets the failure clock without addressing the root design limitations. It’s the right call if the truck needs to stay fully emissions-compliant and budget is tight.
Rebuilt turbos are used cores that have been disassembled, inspected, and reassembled with new bearings, seals, and worn components. Quality varies by rebuilder, so verifying the rebuild standard matters. Exchange programs let you send in your core and receive a fully rebuilt or remanufactured unit in return, often cutting lead time compared to a new unit.
Aftermarket upgraded turbos and full kits offer larger compressor and turbine wheels, different housing configurations, or entirely new platforms (S300, S400) that the factory never used. These are where most buyers land when they want both a reliability fix and a performance improvement.
Once you know the part category that fits your situation, the next question is whether a single turbo or a compound setup is the right architecture.
Single Replacement Vs Compound Systems
The choice between a drop-in single turbo and a compound system is the most consequential spec decision in the upgrade process.
When A Drop-In Setup Makes Sense
A drop-in VGT upgrade, such as an HE363VG or HE366VG with a larger compressor wheel (63mm or 66mm versus the factory 60mm), fits in the factory location and keeps all OEM connections intact. The exhaust brake works, the electronic actuator stays, and the emissions system is undisturbed.
These units support roughly 500-550 RWHP, depending on wheel size. For a tow truck, daily driver, or fleet vehicle that needs reliability improvements and modest power gains without major surgery, a drop-in VGT upgrade is the cleanest path. EGTs typically drop noticeably under load compared to a worn factory unit.
The limitation is that the fundamental architecture remains the same. Vane sticking and actuator wear remain possible failure modes over time, even with an upgraded VGT.
Who Should Consider A Compound Arrangement
A compound setup pairs two turbos in sequence: a smaller high-pressure turbo and a larger low-pressure atmospheric turbo. The result is dramatically lower EGTs (often 200 to 400 degrees Fahrenheit less under load), better combustion efficiency, and power headroom that a single turbo cannot match.
There are two compound paths for the 6.7 Cummins. The first retains the factory VGT as the high-pressure stage and adds a larger S400-platform turbo in front of it. This approach keeps the factory exhaust brake and emissions equipment.
The second replaces the factory VGT entirely with an S300 high-pressure turbo and pairs it with an S400 atmospheric turbo, using a new exhaust manifold. That second path requires the truck to already be deleted.
For owners who tow heavy loads regularly or want to push past 600 RWHP, compound is the right frame to be working in.
Tradeoffs In Cost, Complexity, And Use Case
| Setup | Power Range | Emissions | Exhaust Brake | Relative Cost |
| Drop-in VGT upgrade | Up to 550 RWHP | Intact | Retained | Lowest |
| Add-a-turbo compound (factory VGT stays) | Up to 700 RWHP | Intact | Retained | Moderate |
| S300 swap (single, deleted trucks) | 530 to 775 RWHP | Requires delete | Optional add-on | Moderate |
| Full compound (S300 + S400) | 650 to 1,000+ RWHP | Requires delete | Optional add-on | Highest |
Compound kits involve more piping, more oil feed and drain lines, and more installation labor. That complexity is worthwhile for the right application. For a fleet truck that runs at stock fueling and needs to stay street-legal, the add-a-turbo compound that retains factory equipment is often the best value.
Understanding which architecture fits your truck is only half the equation. The spec and fitment details are where orders go wrong.
Fitment And Spec Checks Before You Order
A kit that physically bolts up but runs wrong is as costly as one that doesn’t fit at all. These three areas cause the most problems.
Turbo Size, Housing, And Exhaust Brake Compatibility
Compressor wheel diameter, turbine housing A/R ratio, and inlet/outlet sizing all affect how the turbo interacts with your existing charge pipe, intake elbow, and intercooler piping. Measure the inner diameter of your charge pipe and verify the compressor outlet size on any kit before ordering. A mismatched charge pipe connection on a 5th gen truck is a common fitment surprise.
If the exhaust brake matters to your operation (and it should if you tow in mountains), confirm whether the kit retains factory brake function or requires an aftermarket exhaust brake solution. The 3rd-gen S300 swap kits eliminate the factory VGT actuator entirely, which means the factory exhaust brake is gone unless you add the optional variable-geometry module.
Fueling, Tuning, And Supporting Hardware Needs
Bigger turbos move more air. More air without matching fuel means lean combustion and no power gain. A larger VGT or an S300 single-turbo upgrade requires a supporting tune. Compound setups often produce gains even at stock fueling because combustion efficiency improves, but tuning is still recommended to get full value.
At higher power levels, consider whether the CP3 injection pump, injectors, and lift pump can support the target output. Intercooler boots and clamps on older 4th gen trucks are a known weak point under increased boost pressure. A kit that targets 650 RWHP on a truck with stock injectors and no tune will not reliably deliver that number.
Ram Pickup Vs Commercial Chassis Differences
The Ram 2500 and 3500 pickup and the 4500/5500 commercial chassis share the 6.7 Cummins engine but differ in hood clearance, cab-to-engine spacing, and sometimes the turbo plumbing routing. Add-a-turbo compound kits designed for the pickup application may require fitment modifications on cab-chassis trucks.
Always verify kit compatibility with your specific chassis configuration, not just the engine family, before placing an order. A parts specialist who knows these chassis differences can catch incompatibilities before they become a return shipment.
Once fitment is confirmed, evaluating kit quality separates durable upgrades from short-lived replacements.
How To Compare Kit Quality And Value
Not all 6.7 Cummins turbo upgrade kits are built to the same standard, and the price difference between a quality kit and a low-cost import can be hard to read from a spec sheet alone.
What Should Be Included In The Box
A complete kit should include the turbocharger itself, all required oil feed and drain hardware, mounting gaskets, a new up-pipe or exhaust connection if the manifold changes, and any electronic connectors or actuator components needed for the application. Compound kits should include all inter-stage piping, clamps, and heat management hardware.
If a kit listing does not itemize what is in the box, that is a red flag. Missing hardware is the most common source of installation delays and return shipments on budget kits.
Signs Of A Lower-Quality Turbo Package
Watch for these indicators before committing to a purchase:
- No listed compressor wheel diameter or turbine A/R ratio in the spec sheet
- Generic photos that don’t match the described application
- No core charge policy or return procedure stated
- Warranty terms that exclude labor or limit coverage to 30 days
- No mention of balancing procedure or bearing type
- Vague fitment claims like “fits all 6.7 Cummins” without year-specific callouts
A turbo that fails six months post-install costs more than the price difference between a budget kit and a quality one.
Warranty, Core Terms, And Parts Availability
OEM exchange turbos typically carry the most defined warranty terms and the clearest core return process. Rebuilt units from established rebuilders usually come with a 12-month warranty, sometimes with unlimited mileage. Aftermarket upgraded kits vary widely. Some manufacturers back their products with multi-year warranties; others offer 90-day warranties with narrow exclusions.
Ask specifically whether the warranty covers the actuator separately from the turbo body. Actuator failures on upgraded VGTs are the most common post-install warranty claim. Availability of replacement actuators and internal components matters as much as the initial warranty term.
When Rebuilt Or Exchange Is The Better Buy
Not every situation calls for a new aftermarket kit. Rebuilt and exchange turbos have a legitimate place in the buying decision for specific scenarios.
Best Cases For A Rebuilt Turbo Option
A professionally rebuilt turbo is the right call when the goal is factory performance restoration rather than a power increase, the truck needs to stay in service fast, and budget is a real constraint. Rebuilt units use the original housing and wheel profiles with new internals, so fitment is exact, and no supporting hardware changes are required.
Fleet applications where a truck needs to stay emissions-compliant and where stock performance is sufficient are the strongest case for a quality rebuilt unit over a new aftermarket kit.
How Exchange Programs Reduce Downtime
Exchange programs are structured so you receive the rebuilt or remanufactured unit before sending in your core. For a shop that cannot afford a multi-day wait on a turbo rebuild, exchange is the fastest path back to service. The core deposit covers the supplier’s risk, and most programs return the deposit promptly upon receipt of the core.
The practical benefit is that the downtime window shrinks to the sum of shipping and installation time. No waiting for your specific unit to be disassembled, inspected, and rebuilt before it ships back.
When A New Aftermarket Kit Is Still Worth It
A new aftermarket kit makes the most sense when the truck is already down for a rebuild, the power or EGT goal exceeds what a factory-profile replacement can achieve, or repeated VGT failures have made it clear that returning to the factory architecture is a losing strategy.
If the engine has been heavily modified or deleted, a new kit designed around the S300 or S400 platform is almost always the stronger long-term investment than a rebuilt OEM-profile turbo, which will hit the same ceiling as the factory unit.
Getting The Right Quote Without Slowing Down The Repair
A fast, accurate quote starts with having the right information ready before you pick up the phone.
Information To Have Ready Before You Call
Suppliers can confirm availability and price immediately when you come prepared. Have these details on hand:
- Exact model year, engine displacement, and cab/chassis configuration
- Factory turbo part number if already removed from the truck
- Current diagnostic codes if the failure is actuator or controls-related
- Power and fueling level (stock, tuned, deleted, or built)
- Whether the exhaust brake must be retained
- Whether you need an exchange, rebuilt, new OEM, or aftermarket upgraded unit
Questions To Ask A Parts Specialist
Ask specifically whether the kit includes the actuator and all gaskets, whether the compressor outlet matches your existing charge pipe diameter, and what the warranty covers. For compound kits, confirm whether inter-stage piping is included or sold separately.
Ask about core charge terms, expected lead time from order to ship, and whether the supplier has handled this specific application before. A specialist who can answer those questions without hesitation has done it before.
Final Buying Priorities For Fast Turnaround
Speed and accuracy matter more than finding the absolute lowest price when a truck is down. Prioritize suppliers who have the unit in stock, can confirm fitment by year and chassis, and can ship same-day or next-day. A $200 savings on a kit that takes two weeks to arrive costs more in downtime than the discount is worth in most fleet or shop contexts.
Match your buying decision to your actual use case, not the highest possible power number. A drop-in VGT upgrade handles most real-world towing and daily-driver needs without the complexity cost of a full compound build.
Frequently Asked Questions
Which Drop-In Turbo Options Fit My Model Year Ram 6.7L Without Changing the Exhaust Manifold or Downpipe?
For 2007.5 to 2018 trucks, upgraded HE363VG and HE366VG units bolt into the factory location using factory manifold and downpipe connections. The 2019 to 2024 5th gen trucks use a proprietary lower-mount flange, so confirm the kit specifically lists 5th gen compatibility before ordering.
What Supporting Mods Do I Need for a Larger VGT: Tuning, Injectors, Lift Pump, Intercooler Boots, and Exhaust?
A tune is required to take full advantage of any upgraded turbo. At power levels above 500 RWHP, injector capacity and CP3 pump output become limiting factors. Intercooler boots and clamps should be inspected and upgraded on high-mileage 4th gen trucks before running elevated boost.
What’s the Realistic Horsepower and EGT Change I’ll See Towing with a 2nd Gen Style Swap Versus a Larger VGT Upgrade?
A larger VGT drop-in typically yields 30-50 RWHP and a moderate EGT reduction under tow. A compound or full S300 swap on a tuned, deleted truck can cut EGTs by 200 to 400 degrees Fahrenheit and open the door to 650 RWHP and beyond, depending on fueling.
Will an Upgraded Turbo Work with the Factory Electronic Actuator, or Do I Need a New Actuator Calibration or Harness Changes?
Drop-in VGT upgrades retain the factory actuator, but it may need recalibration or replacement if it shows signs of wear. Full S300 or S400 swap kits eliminate the factory VGT actuator entirely. If the factory actuator is being reused on a new VGT housing, confirm the position learning procedure with your tuner.
How Do I Verify Compressor Inlet/Outlet Sizes and Charge Pipe Connections to Avoid Fitment Surprises on the Install?
Measure the inner diameter of your existing compressor inlet tube and charge pipe before ordering. Cross-reference those measurements against the kit’s published compressor outlet diameter. Many 5th gen fitment problems come from charge pipe diameter mismatches that are not obvious from the kit photo or listing title.
What’s the Difference in Cost and Lead Time Between OEM Exchange, Rebuilt, and Aftermarket Upgraded Turbo Setups for a 6.7L?
OEM exchange turbos typically cost $1,800 to $2,800 and ship quickly when stock is on hand. Quality rebuilt units fall in a similar price range with slightly longer lead times if the core needs to be processed. New aftermarket upgrade kits range from $1,500 for a basic drop-in to $4,000 or more for a full compound system, including all hardware.
Making The Call on Your Next Turbo Purchase
The right 6.7 Cummins turbo upgrade decision comes down to three things: your power and EGT goal, whether the truck is emissions-compliant or deleted, and whether you need a fast return to service or can invest time in a more involved compound build.
A drop-in VGT upgrade handles most towing and daily-driver needs cleanly. A compound system is the right move when those goals outgrow what a single turbo can deliver.
If you know the engine year, the chassis configuration, and what the truck needs to do, the sourcing conversation is short. The fitment and spec checks covered above are the same ones a good parts specialist will walk through on the call anyway, so going in prepared cuts the time in half.
If you know the engine and the symptom, Turbo Diesel of Oklahoma can match you to the right component today. Call for a quote and get a direct answer from someone who knows this part.