Answers to your Questions


Do I really need TCM tuning?

It’s not absolutely necessary but it is highly recommended for proper shifting & taking into account the final drive ratio.
Our TCM tune addresses shift points, torque management and wide open throttle (WOT) RPM limits imposed by the TCM. The stock TCM tuning WOT shift point is at 3250 RPM because the stock power curve falls off before then.
The power band in the 4th-5th setting of our DSP-5 tune continues past that; By raising the part throttle and WOT shift points to accommodate the increase power band curve, it not only improves the ability to handle the power, protects the transmission and prevents slipping, but also increases the performance of the vehicle because it revs out higher and will improve the acceleration.
We also suggest the TransGo JR shift kit if you are running an Allison 6.

I’m swapping the OEM electronic transfer to a manual shift case; Will that be a problem with either the DSP-5 or the TCM?

The conversion to manual case is not an issue and as long as you are using the factory style t-case the low range ratio should be the same as stock. (Although we can alter that ratio if another style case is used. If you want it to work correctly you will have to be sure to wire in the 4wd low activation sensor/switch to the TCM so that it will know when the truck has been shifted to low range or else it will put the trans in limp mode.

Do you support LGH?

The LGH is a detuned version of the LML engine and was offered in two configurations:

  1. LGH/Allison (cab and chassis trucks and fleet vehicles) These very closely resemble the LML Truck configuration and we do support these drivetrains in conversions.
  2. LGH/6l90 (vans, cutaways, busses) WE DO NOT SUPPORT THIS CONFIGURATION!!!

LML/LGH Swap Info

Do you offer a standalone solution for an LGH with a 6L90E behind it?

At this time we do not offer an LGH/6L90E standalone solution. We do offer an LML Engine only and an LML \ Allison combination.

We have done several 4l80 and a few 6l90 behind earlier motors like LBZ and LMM. From these experiences we can confidently say that the trans is a significant limitation in the drivetrain capability. Due to the much lower torque capacity of these transmissions the engines must be significantly detuned from the factory truck calibration. Similarly, the operating systems for Vans/Cutaways/Ambulances/Bus’, are all specific to the configuration, making it more difficult.

We are currently testing a conversion harness that allows you to couple an LGH to an Allison with some modifications to the engine and should have results on this in the next month or so.


What Shipping Methods Are Available?

Most products are shipped through UPS ground, faster shipping is available upon request. USPS service and FedEx are also available on request.

How quickly will you ship my order.

Shipping varies based on whether we are waiting for your part, have the request forms that may be necessary, have the item in stock, etc. We do our best to move on items/products that are available within 2 business days. We get excited about our orders, so we relate to how you are feeling. If you have any rush requests, please contact us

How Long Will It Take To Get My Package?

Shipping times are estimates at the time of item shipment and tracking numbers are provided when available.

Do You Ship Internationally?

Yes, international shipping is available. Additional fees apply.


What Payment Methods Are Accepted?

Currently all major credit cards are excepted through Stripe and PayPal. A PayPal account is not required to process your cards.

Are there additional payment options

We will possibly accept checks and wire transfer. If you’d like to utilize these options, please contact us


What is the order process?

We provide an introductory page to ordering with us; It explains our procedure, offers recommended items, quick link to the tune request form, and shipping information for your donor. Please review it for a better understanding of how to complete your order.

How do I place an Order?

Create and account, Log in and place your order. All projects are unique in their own way so someone from our company will be in touch with you typically within 24 hours to discuss your project and support your success.

Do I need an account to place an order?

We offer guest checkout but encourage our customers to register for our records and for easy of use on your next visit.

How Do I Track My Order?

Tracking Numbers are provided at the time of product shipment via email.

How Can I Cancel Or Change My Order?

Contact us for any questions or concerns with your order.

How Can I Return a Product?

All returns must receive an RMA number prior to shipping back to DmaxSwap.com in order to receive credit for their return. Most items are not eligible for return.

Any unanswered questions? Contact Us