A strong alternator for a 6.7L Cummins should match your vehicle and charging needs, with higher output for added electrical demand and the correct fit for your Ram, bus, or commercial chassis. Mechman 370A Alternator leads this group with a stated 370-plus amps at cruising speed and more than 200 amps at idle, making it the standout for a Dodge Ram owner seeking substantial output. The other choices span a 300A custom replacement, Ram-specific options with listed model-year fitments, and 200A units for commercial vehicles.
These listings are not interchangeable: confirm the exact vehicle, engine, alternator connections, and pulley before ordering. Use the comparisons below to narrow the candidates, then verify fitment for your specific application.
Mechman 370A Alternator is the leading choice for a Dodge Ram 6.7L Cummins buyer seeking high output. Its listed details call out a large-case, direct-bolt-in design, 6-phase technology, twin rectifiers, more than 200 amps at idle, and 370-plus amps at normal cruising speed. Those figures distinguish it from the other Ram-oriented options here.
Confirm the alternator fits your exact vehicle and charging setup before purchase, since the listing does not provide a complete year-by-year fitment range.
Our Top Picks
Best OverallIts Dodge Ram 6.7L listing specifies 370-plus amps at cruising speed and more than 200 amps at idle, alongside 6-phase technology and twin rectifiers.
View on Amazon
Later Ram FitmentThe title specifies a Ram 2500 6.7L fit for a broad later-model range, making it a direct candidate for those listed trucks.
View on Amazon
High-Output OptionThis custom 300A unit lists Dodge Ram 2500 and 3500 6.7L applications, plus 6-phase hairpin technology and an 8-groove clutch pulley.
View on Amazon- OE-Style Replacement A-Premium 136A Alternator
Compare these alternator options
| # | Product | Weight | Voltage | Package Dimensions | Buy |
|---|---|---|---|---|---|
| 1 | 1. Mechman 370A AlternatorBest Overall | 20 lb | — | 10 x 9.5 x 9.5 in | View on Amazon |
| 2 | 2. ASAPE 11379 AlternatorLater Ram Fitment | 17.17 lb | — | 9.45 x 7.87 x 7.09 in | View on Amazon |
| 3 | 3. LActrical 300A AlternatorHigh-Output Option | 18 lb | 14 V | — | View on Amazon |
| 4 |  4. A-Premium 136A AlternatorOE-Style Replacement | 16.46 lb | — | 10.91 x 8.46 x 7.56 in | View on Amazon |
| 5 |  5. Gladiator 200A FreightlinerFreightliner chassis replacement | 18 lb | 12 V | — | View on Amazon |
| 6 |  6. Gladiator 200A Bus AlternatorBus and medium-duty 6.7L fitment | 19 lb | 12 V | — | View on Amazon |
Detailed Reviews: Best Alternator For 6 7 Cummins
#1 · Best Overall
1. Mechman 370A Alternator
- Weight: 20 lb
- Package Dimensions: 10 x 9.5 x 9.5 in
Best for: High idle-output Ram upgrade.
Why it ranks #1: Its Dodge Ram 6.7L listing specifies 370-plus amps at cruising speed and more than 200 amps at idle, alongside 6-phase technology and twin rectifiers.
Mechman specifies more than 200 amps at idle and over 370 amps at normal cruising, making this 370-amp alternator particularly relevant to Ram 6.7L Cummins owners who need substantial output at low engine speed. Its large-case hairpin design and direct-bolt-in description distinguish it as a high-output daily-use option.
The stated 200-plus amps at idle can support electrical demand before the engine reaches cruising speed, while the 370-plus-amp figure at normal cruising indicates greater output as engine speed rises. Mechman pairs that performance with six-phase technology and twin rectifiers, which it describes as durable for daily use, including abusive applications. The large-case unit is presented as a direct bolt-in for Dodge Ram 6.7L trucks, offering a specified installation approach without a listed model-year range.
- 370-plus amps at normal cruising, as stated
- 200-plus amps at idle, as stated
- Six-phase technology with twin rectifiers
- Described as a direct bolt-in alternator
- The listing does not provide a model-year range for the Ram 6.7L fitment.
Skip it if you need a stated year range for a 2013–2022 Ram 2500; ASAPE 11379 explicitly lists those model years.
This is a strong candidate for a Ram 6.7L owner seeking high output at idle as well as at cruising speed, including daily or demanding use. The direct-bolt-in description helps, but the listing leaves model years unspecified.
Full product details
| Brand | Mechman Alternators |
|---|---|
| Item Weight | 20 pounds |
| Item model number | 11378370 |
| Manufacturer | Mechman Alternators |
| Part Number | 11378370 |
| Package Dimensions | 10 x 9.5 x 9.5 inches |
Listed on Amazon as: Mechman 370 Amp Alternator For Dodge Ram 6.7L Cummins Diesel
View on Amazon#2 · Later Ram Fitment
2. ASAPE 11379 Alternator
- Weight: 17.17 lb
- Package Dimensions: 9.45 x 7.87 x 7.09 in
Best for: Later-model Ram 2500 replacement.
Why it ranks #2: The title specifies a Ram 2500 6.7L fit for a broad later-model range, making it a direct candidate for those listed trucks.
A stated 2013–2022 Ram 2500 6.7L application is the defining feature of the ASAPE 11379, directing it toward owners of later-model Cummins pickups. The product facts identify it as a replacement alternator and give its model identifier and package weight, but do not state an amperage or voltage rating.
The title identifies Ram 2500 6.7L fitment from 2013 through 2022, making the model-year span the main practical selection detail for owners seeking a replacement. Its listed model identifier and manufacturer part number can help distinguish this unit when comparing parts information. ASAPE advises buyers to use the model table or consult the seller to confirm the product, a useful step given the wide year range. No output rating is provided in the supplied facts.
- Named fitment for Ram 2500 6.7L
- 2013–2022 model-year range is stated
- Identified as an alternator replacement
- Model identifier and manufacturer part number are provided
- The supplied product details do not state an amperage or voltage rating.
Skip it if you want a stated high-output rating for an early Ram; LActrical LA11239HO300A lists 300 amps for 2007–2009 trucks.
Consider this ASAPE replacement if your truck is a Ram 2500 6.7L within the stated 2013–2022 range. Its fitment span is useful, but buyers who need a documented amperage or voltage figure should account for that missing specification.
Full product details
| Brand | ASAPE |
|---|---|
| Item Weight | 17.17 pounds |
| Item model number | 119461-5460-1023080185 |
| Manufacturer | ASAPE |
| Part Number | 119461-5460-1023080185 |
| Model | Alternator |
| Package Dimensions | 9.45 x 7.87 x 7.09 inches |
Listed on Amazon as: ASAPE 11379 New Alternator Fit for 2013-2022 for Ram for 2500 6.7L
View on Amazon#3 · High-Output Option
3. LActrical 300A Alternator
- Weight: 18 lb
- Voltage: 14 V
Best for: High-output early Ram upgrade.
Why it ranks #3: This custom 300A unit lists Dodge Ram 2500 and 3500 6.7L applications, plus 6-phase hairpin technology and an 8-groove clutch pulley.
A 300-amp rating paired with six-phase hairpin technology gives this LActrical alternator a clear role for early Dodge Ram 2500 and 3500 owners seeking more charging capacity. Its compact-package design and 96-slot stator are the key differentiators, while the listing specifies a 2007–2009 6.7L Cummins application.
The 300-amp output and six-phase hairpin construction target charging demands beyond a standard replacement, while the 96-slot stator is specified as more efficient than a 36-slot design. LActrical also says the unit uses less horsepower than conventional three-phase alternators, a practical consideration for a truck working under load. Its 8-groove clutch pulley and specified 14-volt output help define the installation match; the seller recommends a fused 4-gauge main charging wire for maximum current.
- 300-amp high-output rating
- Six-phase hairpin technology
- 96-slot stator specified for greater efficiency than a 36-slot design
- 8-groove clutch pulley and 14-volt output are listed
- The listed application is limited to 2007–2009 Ram 2500 and 3500 6.7L trucks.
Skip it if you need a listed 2013–2022 Ram 2500 application; ASAPE 11379 names those model years instead.
Choose this for a 2007–2009 Ram 2500 or 3500 6.7L owner prioritizing a 300-amp upgrade and higher charging output. Its stated fit range is narrow, and the fused 4-gauge charging-wire recommendation matters to installation planning.
Full product details
| Brand | LActrical |
|---|---|
| Item Weight | 18 pounds |
| Manufacturer | LActrical |
| Part Number | LA11239HO300A |
| Voltage | 14 volts |
| Additional Information | Important information |
Listed on Amazon as: High Output 300 Amp Alternator compatible with Dodge Ram 2500 3500 Pickup Truck Cummins Diesel 6.7L 07 2007 08 2008 09 2009 custom
View on Amazon#4 · OE-Style Replacement
4. A-Premium 136A Alternator
- Weight: 16.46 lb
- Package Dimensions: 10.91 x 8.46 x 7.56 in
Best for: Stock-output early Ram replacement.
Why it ranks #4: Its listing specifies 12V, 136A, clockwise rotation, and fitment for Ram 2500 and 3500 6.7L trucks in the stated application range.
A 136-amp rating, 12-volt output, and clockwise rotation define this A-Premium alternator for early Dodge Ram 2500 and 3500 6.7L applications. Its fitment also covers Ram 4500 and 5500 models in specified years, making the stated vehicle range—not a high-output claim—the key buying distinction.
A-Premium lists Ram 2500 and 3500 fitment for 2007–2009 and Ram 4500 and 5500 fitment for 2008–2010, all with L6 6.7L engines. That explicit range helps narrow the application, while the 136-amp, 12-volt specification and clockwise rotation identify the electrical and mechanical details. The SC8 pulley class and eight-groove pulley description further support checking the replacement against the vehicle’s existing setup. The manufacturer says the unit is made to OE standards.
- 136-amp rating at 12 volts
- Clockwise rotation specified
- SC8 pulley class with an 8-groove pulley
- Listed fitment includes Ram 2500/3500 and Ram 4500/5500 6.7L
- Its 136-amp rating is well below the listed 300-amp LActrical alternative.
Skip it if you need substantially more charging output than 136 amps; LActrical LA11239HO300A lists a 300-amp rating for 2007–2009 Ram 2500 and 3500 models.
This fits buyers seeking a specified 136-amp replacement for a listed 2007–2009 Ram 2500 or 3500, or 2008–2010 Ram 4500 or 5500. Its output is a boundary for owners who need a high-output upgrade.
Full product details
| Brand | A-Premium |
|---|---|
| Item Weight | 16.46 pounds |
| Manufacturer | PremiumpartsWhosale |
| Part Number | 0APALT121 |
| Package Dimensions | 10.91 x 8.46 x 7.56 inches |
Listed on Amazon as: A-Premium Alternator, 12V 136A 8-Groove Pulley CW, Compatible with Dodge
View on Amazon#5
5. Gladiator 200A Freightliner
- Weight: 18 lb
- Voltage: 12 V
Best for: Freightliner chassis replacement.
Why it ranks #5: This 12V, 200A alternator lists Freightliner chassis with Cummins ISB 6.7L fitment, but targets commercial chassis rather than Ram pickups.
A 200-amp rating and a stated Freightliner chassis application make this Gladiator alternator relevant to medium-duty Cummins 6.7L owners. It is computer load tested and specified to meet or exceed OEM specifications, pairing a familiar replacement target with a listed 12-volt output and coverage across multiple engine families.
For a Freightliner B2 chassis with a Cummins ISB 6.7L in the listed 2013–2016 years, the application detail gives buyers a concrete starting point for a replacement. The 200-amp rating and 12-volt specification describe its electrical output, while computer load testing provides a stated reliability check before installation. OEM-specification performance is also claimed. Its broader engine range includes Caterpillar, Detroit, and Mercedes-Benz applications, so the exact chassis and engine listing remains central to selection.
- 200-amp alternator rating
- 12-volt specification
- 100% computer load tested, according to the listing
- Meets or exceeds OEM specifications, according to the listing
- Its listed 6.7L applications are Freightliner chassis fitments, not Ram pickup fitments.
Skip it if you have a Ram pickup rather than a listed Freightliner chassis; LActrical LA11239HO300A lists Ram 2500 and 3500 applications.
This suits buyers replacing an alternator on a listed Freightliner chassis with a Cummins ISB 6.7L, particularly where OEM-level specifications and computer load testing matter. The application is chassis-specific, so use its detailed fitment rather than the engine size alone.
Full product details
| Brand | Gladiator |
|---|---|
| Item Weight | 18 pounds |
| Manufacturer | Gladiator |
| Part Number | 8600253 |
| Dimensions | 9 x 9 x 6.5 inches |
| Voltage | 12 volts |
#6
6. Gladiator 200A Bus Alternator
- Weight: 19 lb
- Voltage: 12 V
Best for: Bus and medium-duty 6.7L fitment.
Why it ranks #6: Its 12V, 200A specification suits listed buses and commercial vehicles with Cummins ISB 6.7L engines, not the typical Ram pickup application.
A broad commercial-vehicle application list—including Bluebird buses with Cummins ISB 6.7L engines from 2008–2016—sets this Gladiator alternator apart from Ram pickup replacements. Its 200-amp, 12-volt specifications and computer load testing give fleet and chassis buyers concrete electrical and inspection details to consider.
The 200-amp output and 12-volt specification define the electrical profile, while computer load testing is a stated check before installation. The application list names Bluebird Bus Cummins ISB 6.7L models for 2008–2016 and also includes several commercial chassis and engine combinations. That breadth can help buyers working across vehicle types, but it also makes exact chassis and engine matching essential. Gladiator says the alternator meets or exceeds OEM specifications.
- 200-amp alternator rating
- 12-volt specification
- 100% computer load tested, according to the listing
- Listed Bluebird Bus Cummins ISB 6.7L fitment for 2008–2016
- Its listed 6.7L applications focus on buses and commercial chassis, not Ram pickups.
Skip it if you need a Ram pickup-specific 2007–2009 high-output unit; LActrical LA11239HO300A lists that application and 300 amps.
Choose this Gladiator for a listed Bluebird bus or commercial chassis application where the 200-amp, 12-volt specification and load testing suit the replacement workflow. Its commercial fitments are not a substitute for a Ram pickup-specific application.
Full product details
| Brand | Gladiator |
|---|---|
| Item Weight | 19 pounds |
| Manufacturer | Gladiator |
| Part Number | 4022170C91 4024553C91 4024553C92 |
| Dimensions | 9.5 x 8.5 x 5.8 inches |
| Voltage | 12 volts |
Avoid the Ram-versus-commercial fitment trap
The biggest fitment trap is treating every 6.7L Cummins alternator as interchangeable across pickups and commercial vehicles. Gladiator 200A Freightliner lists Freightliner chassis with Cummins ISB 6.7L applications, while Gladiator 200A Bus Alternator names buses and several commercial vehicle types. Neither listing is a general Ram pickup fitment claim.
For Ram buyers, ASAPE 11379 Alternator names Ram 2500 6.7L, LActrical 300A Alternator names Ram 2500 and 3500 applications, and A-Premium 136A Alternator specifies Ram 2500/3500 fitment. Mechman 370A Alternator is described for a Dodge Ram 6.7L, but its supplied details do not give a full year range.
Match the vehicle, engine, and application in the seller’s fitment information; engine displacement alone is not enough to establish compatibility.
High output can require charging-system planning
A higher amp rating is not the only factor to consider when changing alternators. Mechman 370A Alternator lists 370-plus amps at normal cruising speed and more than 200 amps at idle, while LActrical 300A Alternator is a 300A custom unit. By comparison, A-Premium 136A Alternator is rated at 136A, and the two Gladiator commercial units are 200A.
The LActrical listing specifically recommends installing a fused 4-gauge main charging wire to allow maximum current. That makes wiring an important compatibility and installation check for a high-output replacement, rather than an assumption that the original charging lead is adequate.
Consider the loads and installation requirements for your vehicle, and verify wiring, fuse, pulley, and connection details before choosing a higher-output unit.
How to Choose a 6.7L Cummins Alternator
Vehicle and engine fitment
Start by matching the alternator to the exact vehicle and engine application. The listings range from Ram-specific options to commercial-chassis parts: ASAPE 11379 Alternator names a Ram 2500 6.7L; LActrical 300A Alternator lists Ram 2500 and 3500 trucks; and A-Premium 136A Alternator lists Ram 2500/3500 and Ram 4500/5500 applications. Gladiator 200A Freightliner instead lists Freightliner chassis, while Gladiator 200A Bus Alternator covers buses and commercial vehicles.
Mechman 370A Alternator is listed for Dodge Ram 6.7L but does not provide a complete year range in the supplied details. Choose the listing that matches your vehicle class, then confirm exact fitment before ordering.
Output rating and use
Choose an output rating that suits your vehicle’s electrical demand, and do not assume the largest figure is automatically the right fit. The listed ratings span 136A for A-Premium 136A Alternator, 200A for each Gladiator unit, 300A for LActrical 300A Alternator, and 370A for Mechman 370A Alternator. Mechman also states more than 200 amps at idle and 370-plus amps at cruising speed.
For a standard replacement, the lower-rated Ram-specific option may be the more relevant comparison; buyers seeking greater output can consider the 300A or 370A choices, provided the vehicle and charging setup are compatible. The Gladiator ratings apply to their stated commercial applications.
Pulley and electrical details
Check pulley and electrical specifications against the alternator being replaced. A-Premium 136A Alternator specifies 12V, clockwise rotation, and an 8-groove pulley; LActrical 300A Alternator specifies 14 volts, clockwise rotation, and an 8-groove clutch pulley. The Gladiator 200A Freightliner and Gladiator 200A Bus Alternator each list 12V.
These differences matter when selecting a direct replacement or changing output capacity, so compare the vehicle’s existing unit and verify connector, regulator, and pulley compatibility. If you are choosing the LActrical 300A Alternator, note that its listing recommends a fused 4-gauge main charging wire.
Buyers who want a straightforward replacement should prioritize matching existing electrical and pulley details over selecting by amp rating alone.
Which 6.7L Cummins Alternator Should I Choose?
For a Dodge Ram 6.7L buyer prioritizing high output, choose Mechman 370A Alternator: it lists 370-plus amps at cruising speed and more than 200 amps at idle. If your Ram 2500 falls within the fitment stated in its title, ASAPE 11379 Alternator is a Ram-specific option. For a listed Ram 2500 or 3500 application needing a 300A unit, consider LActrical 300A Alternator and check its recommended fused 4-gauge charging wire.
A-Premium 136A Alternator is the lower-output choice with stated Ram fitment and a 12V, clockwise, 8-groove specification. For commercial vehicles, use Gladiator 200A Freightliner or Gladiator 200A Bus Alternator only when its listed chassis or vehicle application matches.
Verify exact fitment before ordering.
Related Buying Guides
Frequently Asked Questions
How can I confirm an alternator will fit my exact Ram 6.7L Cummins?
Confirm fitment using your Ram’s year, model, engine, and existing alternator configuration, then compare those details with the listing’s stated applications. Do not rely on engine size alone: these listings provide different vehicle ranges, and the Mechman listing does not give a complete year-by-year range. Check with the seller or a qualified parts professional if details are unclear.
Will a higher-output alternator require an upgraded charging wire or other electrical changes?
It may, so verify the wiring and protection requirements for the specific alternator and vehicle before installation. The LActrical 300A listing recommends a fused 4-gauge charging wire; do not assume that recommendation applies to every option. Check the alternator instructions and your vehicle’s charging setup, and have a qualified installer assess any required changes.
What should I check before replacing an alternator to diagnose a charging problem?
Check the battery condition, terminals, grounds, belt, and charging connections before replacing the alternator. Look for loose, corroded, or damaged wiring, and confirm the charging-system warning or voltage symptoms with appropriate tests. A weak battery or connection problem can resemble alternator failure, so diagnose the full charging system rather than assuming the alternator is the cause.
Can a commercial-vehicle alternator be used in a Ram pickup?
Only if its listed vehicle application and physical and electrical fitment match your exact Ram; a similar engine size is not enough to establish compatibility. The Freightliner and Bluebird bus listings describe commercial applications, not general Ram pickup fitment. Confirm the application with the seller or a qualified parts professional before ordering or installing one.
How should I choose between a higher-output and a lower-output option?
Choose output based on your vehicle’s verified fitment and electrical needs, not the rating alone. The Mechman listing specifies 370-plus amps at cruising speed and more than 200 amps at idle, while the A-Premium listing specifies 136A. Confirm compatibility and any wiring requirements; the listed output figures do not by themselves guarantee suitability for your setup.
Final Words
For a Dodge Ram 6.7L buyer prioritizing output, the Mechman is the leading choice based on its listed idle and cruising figures, but verify exact fitment first. Consider the ASAPE for a Ram 2500 within its stated application, or the LActrical 300A for a listed Ram 2500 or 3500 and check its fused 4-gauge wire recommendation. Choose the A-Premium for its stated fitment and lower output; reserve the Gladiator units for matching commercial applications.
